# 1 Chemical Reactions and Equations

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 1 Intext Questions On Page 6 Question 1. Why should a magnesium ribbon be cleaned before burning in air? Magnesium ribbon reacts with CO present in air to form a protective and inert layer of magnesium carbonate. This layer is unreactive and hence, needs to be cleaned before burning in air. Question. Write the balanced equation for the following chemical reactions. (i) Hydrogen chlorine hydrogen chloride (ii) Barium chloride + aluminium sulphate barium sulphate + aluminium chloride (iii) Sodium + water sodium hydroxide hydrogen (i) The symbol/formulae of hydrogen, chlorine and hydrogen cholride are H, Cl and HCl respectively. Thus, the simplest equation is H Cl HCl Reactant Product Now the balancing is done in following steps. Step I Count the number of atoms of each elements on the reactant and product side of the equation. LHS RHS H 1 Cl 1 Step II In order to equalate the number of H atoms, write in the equation before HCl. Now the equation becomes. Step III sides. H + Cl HCl Count further the number of atoms of each element on both At LHS At RHS No. of H atoms No. of Cl atoms No. of H atoms No. of Cl atoms Now the number of atoms of each element are equal on both the sides. Thus, H() g Cl HCl( g) is the balanced equation for the given reaction. (Where, g represents the gaseous state).

2 (ii) Formula of barium chloride, aluminium sulphate, barium sulphate and aluminium chloride is respectively BaCl,Al (SO 4),BaSO 4, AlCl. So, the unbalanced equation is BaCl Al (SO 4) BaSO4 AlCl on balancing the above equation [by the similar method as shown for (i)] we get BaCl Al (SO 4) BaSO 4+ AlCl (iii) Similary balanced equation for the give reaction is Na + HO NaOH + H Question. Write a balanced chemical equation with state symbols for the following reactions. (i) Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride. (ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to form sodium chloride solution and water. (i) In this reactants are barium chloride (BaCl ) and sodium sulphate (NaSO 4) and products are barium sulphate (BaSO 4) and sodium chloride (NaCl). So the balanced equation is BaCl( aq) NaSO4( aq) BaSO4 () s NaCl ( aq) Barium chloride Sodium sulphate Barium sulphate Sodium chloride (ii) In this reaction, sodium hydroxide (NaOH) and hydrogen chloride (HCl) are reactants and sodium chloride (NaCl) and water (HO) are the products so, the balanced equation for this reaction is NaOH ( aq) HCl ( aq) NaCl ( aq) HO () l Sodium hydroxide Hydrogen chloride Sodium chloride Water On Page 10 Question 1. A solution of substance X is used for white washing. (i) Name the substance X and write its formula. (ii) Write the reaction of substance X named in (i) with water. (i) We use quicklime solution for white washing. Hence, X is quicklime (CaO). (ii) Quicklime + water slaked lime + heat CaO () s + HO () l Ca(OH) ( aq) ( X) The reaction is highly exothermic and a lot of heat is produced. Question. Why is the amount of gas collected in one of the test tubes in activity 1.7 double of the amount collected in another? Name this gas. The activity 1.7 of NCERT book is electrolysis of water. During electrolysis of water, water decomposes to form hydrogen and oxygen gases. Electrolysis H O () l H ( g) + O ( g)

3 The balanced equation shows clearly that the water decomposes during electrolysis to form hydrogen and oxygen gases in the ratio : 1 by volume. Hence, the amount of hydrogen gas collected is twice or double the amount of oxygen collected. The gas is hydrogen. On Page 1 Question 1. Why does the colour of copper sulphate solution change when an iron nail is dipped in it? CuSO4 ( aq) + Fe ( s) FeSO4 ( aq) + Cu ( s) ( Blue) (Green) The above equation clearly shows that the colour of solution changes from blue to green. This is actually a displacement reaction in which a more reactive element displaces a less reactive element from its salt solution. Iron being more reactive than copper displaces copper from CuSO 4 solution (blue) to form FeSO 4 (green). Hence, change in colour is observed. Question. Give an example of double displacement reaction other than the one given in activity AgNO ( aq) + NaCl ( aq) AgCl () s + NaNO ( aq) Silver nitrate Sodium chloride Silver chloride Sodium nitrate Question. Identify the substances that are oxidised and substances that are reduced in the following reactions. (i) 4Na() s + O () s Na O() s (ii) CuO() s + H ( g) Cu () s + H O() l (i) 4 Na() s + O () g Na O() s In this reaction, Na has gained oxygen so, Na is oxidised to Na O. Here O is the oxidising agent It is itself getting reduced. Reduced 4Na () s + O() g NaO() s Oxidised Oxidised (ii) CuO ( s) + H( g) Cu ( s) + HO () l Reduced CuO is losing oxygen to form Cu ( s) so it is getting reduced and H () g is gaining this oxygen so it is getting oxidised.

4 Exercises Question 1. Which of the statements about the reactions below are incorrect? PbO () s + C () s Pb () s + CO ( g) (i) Lead is getting reduced (ii) CO is getting oxidised (iii) Carbon is getting oxidised (iv)lead oxide is getting reduced (a) (i) and (ii) (b) (i), (ii) and (iii) (c) (i) and (iii) (d) All of these (a) (i) and (ii) are incorrect. In the backward reaction, oxygen is added to lead (Pb) so Pb is getting oxidised to PbO and oxygen is removed from CO, so, it is getting reduced to C (Because addition of oxygen is oxidation and removal of oxygen is reduction.) Question. FeO + Al AlO + Fe The above reaction is an example of a (a) combination reaction (b) double displacement reaction (c) decomposition reaction (d) displacement reaction (d) In the above reaction since Al is more reactive than Fe so it displaces Fe from Fe O to form Al O. Hence, it is a displacement reaction. Question. What happens when dil. HCl is added to iron fillings? Tick the correct answer. (a) Hydrogen gas and iron chloride are produced (b) Chlorine gas and iron hydroxide are produced (c) No reaction takes place (d) Iron salt and water are produced (a) Iron being more reactive than hyrogen, displaces hydrogen from the dilute acids like dilute HCl. Thus, hydrogen gas and iron chloride are formed. Fe () s + HCl () l FeCl + H Question 4. What is a balanced chemical equation? Why should chemical equations be balanced? A chemical change is represented by a chemical equation. When the number. of atoms of different elements on reactant and product side are equal then the chemical equation is called a balanced chemical equation. It is important to balance a chemical equation because 1. to validate the law of conservation of mass which states that the mass of reactants should be equal to the mass of the products. The total mass of a system is thus conserved. This law holds true only if number. of atoms of reactants reacting together is equal to number of product atoms formed.. a balanced chemical equation tells us about the physical state of the reactants and products whether they are solid (s), liquid () l or gas () g or aqueous ( aq ).

5 . it tells us about heat changes that can take place in a chemical reaction. is the symbol of heat. Hence, it is endothermic or exothermic can be deduced from a balanced chemical equations. Question 5. Translate the following statements into chemical equation and then balance them. (a) Hydrogen gas combines with nitrogen to form ammonia. (b) Hydrogen sulphide gas burns in air to give water and sulphur dioxide. (c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate. (d) Potassium metal reacts with water giving potassium hydroxide and hydrogen gas. (a) The symbol equation for the reaction is H + N NH The balancing of equation is done in the following steps: Step I Let us count the number of atoms of all the elements of the reactants and the products on both sides of the equation. H N 1 A simple look at the equation reveals that neither the number of H nor of N atoms are equal on both side of the equation. Step II In order to equate the number of H atoms on both sides, put coefficient before H on the reactant side and coefficient before NH on the product side. H + N NH Step III On counting, the number of N atoms on both sides of the equation, they are also the same (). This means that equation is balanced. (b) The symbol equation for the reaction is HS + O HO + SO The balancing of equation is done in the following steps: Step I Let us count the number of atoms of all the elements on both sides on the equation. H S 1 1 O

6 A simple look at the equation reveals that the number of H and S atoms are equal on both the sides. At the same time, the number of O atoms are not equal. Step II In order to equate the number of O atoms, put coefficient before O on the reactant side and coefficient before SO on the product side. HS + O HO + SO Step III O atoms are still not balanced. To achieve this, put coefficient before HO on the product side. HS + O HO + SO Step IV To balance S atoms put coefficient before HSO4 the reactant side. HS + O HO + SO Step V On inspection, the number of atoms of all the elements in both side of the equation are equal. Therefore, the equation is balanced. (c) The symbol equation for the reaction is BaCl + Al( SO4) ACl + BaSO4 The balancing of equation is done in the following steps. Step I Let us count the number of atoms of all the elements on both sides of the equation. Ba 1 1 Al 1 Cl S 1 O 1 4 A simple look at the equation reveals that only Ba atoms are equal on both the sides. The rest of the atoms are to be balanced. It is done as follows Step II In order to equate the number of Al atoms, put coefficient before AlCl on the product side. BaCl + Al ( SO ) AlCl + BaSO 4 4 Step III In order to balance Cl atoms, put coefficient before BaCl on the reactant side. BaCl + Al ( SO ) AlCl + BaSO 4 4 Step IV To balance Ba atoms, put cofficient before BaSO 4 on the product side. BaCl + Al ( SO ) AlCl + BaSO 4 4 Step V On inspection, the number S and O atoms on both sides of the equation are also found to be equal. Thus, the equation is in balanced form. (d) The symbol equation for the reaction is K + HO KOH + H The balancing of the equation is done in the following steps :

7 Step I Let us count the number of atoms of all the elements on both sides. K 1 1 H O 1 1 A simple look at the equation reveals that the number of K and O atoms on both sides of the equation are equal. At the same time, the number of H atoms are not equal. Step II To balance the number of H atoms, put coefficient before KOH on the product side and before HO on the reactant side. K + HO KOH + H Step III To balance the number of K atoms in the above equation, put coefficient before K atom on the reactant side. K + H O KOH + H Step IV On inspection, the number of atoms of all the elements are found to be equal on both sides of the equation. It is finally balanced. Question 6. Balance the following chemical equations. (a) HNO + Ca(OH) Ca(NO ) + HO (b) NaOH + HSO4 NaSO 4 + HO (c) NaCl + AgNO AgCl + NaNO (d) BaCl + H SO BaSO + HCl 4 4 (a) The symbol equation as given for the reaction is HNO + Ca(OH) Ca(NO ) + HO The balancing of the equation is done in the following steps. Step I. Let us count the number of atoms of all the elements on both the sides of the equation. H O 5 7 N 1 Ca 1 1 A simple look at the equation reveals that the number of Ca atoms are equal on both sides. Step II In order to equate the number of N atoms, put coefficient before HNO on the reactant side. HNO + Ca(OH) Ca(NO ) + HO Step III In order to equate the number of H atoms, put coefficient before HO on the product side. HNO + Ca(OH) Ca(NO ) + HO Step IV On inspection the number of O atoms on both sides of the equation is the same, i.e., 8. Therefore, the equation is balanced.

8 (b) The symbol equation as given for the reaction is NaOH+HSO4 NaSO 4 +HO Step I Let us count the number of atoms of all the elements on both sides of the equation. H O 5 5 Na 1 S 1 1 A simple look at the equation reveals that the number of O and S atoms are equal on both sides. Step II In order to equate the number of Na atoms, put coefficient before NaOH on the reactant side. NaOH+HSO4 NaSO 4 +HO Step III In order to equate the number of H atoms, put coefficient before HO on the product side. NaOH+HSO4 NaSO 4 +HO Step IV On inspection, the number of O atoms on both sides of the equation is the same i.e. 6. Therefore, the equation is balanced. (c) The symbol equation as given for the reaction is already balanced. NaCl + AgNO AgCl + NaNO (d) The symbol equation as given for the reaction is BaCl + HSO4 BaSO4 + HCl Step I Let us count the number of atoms of all the elements on both sides of the equation. Ba 1 1 H 1 O 4 4 S 1 1 Cl 1 A simple look at the equation reveals that the number of Ba, S and O atoms are equal on both the sides. Step II In order to equate the number of Cl atoms, put coefficient before HCl on the product side. BaCl` + HSO4 BaSO4 + HCl Step III On inspection the number of H atoms on both sides of the equation is the same i.e.. Therefore, the equation is balanced. Question 7. Write the balanced chemical equation for the following reactions. (a) Calcium hydroxide + carbon dioxide calcium carbonate + water (b) Zinc + silver nitrate zinc nitrate + silver

9 (c) Aluminium + copper chloride aluminium chloride + copper (d) Barium chloride + potassium sulphate barium sulphate + potassium chloride (a) Ca(OH) + CO CaCO + HO (b) Zn + AgNO Zn (NO) + Ag (c) Al + CuCl AlCl + Cu (d) BaCl + KSO4 BaSO4 + KCl Question 8. Write the balanced chemical equation for the following and identify the type of chemical reaction. (a) Potassium bromide ( aq ) + barium iodide ( aq) potassium iodide ( aq ) + barium bromide () s. (b) Zinc carbonate () s zinc oxide () s + carbon dioxide ( g) (c) Hydrogen ( g ) + chlorine ( g) hydrogen chloride ( g) (d) Magnesium () s + hydrochloric acid ( aq) magnesium chloride ( aq ) + hydrogen ( g) (a) KBr ( aq) + BaI ( aq) KI ( aq) + BaBr () s (Double displacement reaction) (Br is replaced by I and I is replaced by Br in KBr and BaI respectively.) (b) ZnCO() s ZnO() s + CO() g (Decomposition reaction (because one compound splits into two compounds) (c) H() g + Cl() g HCl( g) (Combination reaction) (because two reactants combine to form a single product) (d) Mg( s) + HCl ( aq) MgCl ( aq) + H ( g) (Displacement reaction) (because H is replaced by Mg) Question 9. What does one mean by exothermic and endothermic reactions? Give equations. On the basis of heat changes that take place during a chemical reaction we have two types of reactions exothermic and endothermic. Chemical reactions on the basis of heat changes heat is absorbed by reactants heat is released + heat heat endothermic exothermic In exothermic reactions energy of reactants is greater than energy of products. Example CH 4 + O CO + HO + Heat Methane Oxygen C + O CO + Heat

10 In endothermic reactions energy of products is greater than the energy of reactants. Example HgO( s) + Heat Hg () l + O ( g) N () g + O () g + Heat NO() g Note We write + Heat with products in exothermic reactions and +Heat with reactants in endothermic reactions. Question 10. Why is respiration considered as exothermic reaction? Explain. When we eat food we are actually consuming different nutrients like fats, proteins and carbohydrates. When the process of digestion begins in the body these complex nutrients are broken down into simpler forms like glucose and fatty acids due to the action of various enzymes. This reaction releases heat. During respiration, the air we breathe oxidises the glucose and fatty acids formed due to digestion and CO and HO are released with heat. Since, heat is released therefore respiration is exothermic in nature. C6H1O 6 + O 6CO + 6HO+Heat Glucose (from air) (Chemically Respiration) Question 11. Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions. As the name suggests when two or more substances combine together to form a new substance, it is called combination reaction. e.g., CaO + CO CaCO H + O HO In decomposition reactions just the opposite happens. One substance splits to give two or more simpler substances. Hence, it is the opposite of combination. CaCO FeSO CaO + CO 4 FeO + SO + SO Question 1. Write one equation each for decomposition reaction where energy is supplied in the form of heat, light or electricity? (i) CaCO ( s) CaO ( s)+ CO Light (ii) AgBr ( s) Ag ( s) + Br ( g) (iii) H O () l Electricity H ( g) + O ( g) Question 1. What is the difference between displacement and double displacement reactions. Write equation. I. Displacement reaction CuSO ( aq) + Fe( s) FeSO ( aq) + Cu( s) 4 4 (Blue) (Green) In this reaction since Fe is more reactive than Cu so it displaces Cu from CuSO 4 and forms FeSO 4 and sets Cu free. Hence, colour of solution changes from blue to green.

11 This is single displacement reaction. II. Double displacement reaction e.g., AgNO ( aq) + NaCl ( aq) AgCl () s + NaNO ( aq) In this reaction displacement occurs twice and mutual exchange of ions takes place between AgNO and NaCl and hence it is a double displacement reaction. AgNO + NaCl AgCl + NaNO ( aq) Question 14. In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved. The chemical equation of the displacement reaction is Cu () s + AgNO ( aq) Cu(NO ) ( aq) + Ag () s Copper Silver nitrate Copper nitrate Silver Question 15. What do you mean by precipitation reaction? Explain by giving examples. An insoluble product formed during a chemical reaction is called a precipitate. It is denoted by a downward arrow ( ). Those reactions in which reactants react to form a product which is insoluble and separates out in the form of a precipitate is called a precipitation reaction. e.g., AgNO ( aq ) + NaCl ( aq ) AgCl ( s ) + NaNO ( aq) Na SO ( aq) + BaCl ( aq) BaSO ( s) + NaCl ( aq) 4 4 Question 16. Explain the following in terms of gain or loss of oxygen with two examples each. (a) Oxidation (b) Reduction When oxygen is gained by a chemical substance, it is called oxidation. e.g., C + O CO Mg + O MgO When oxygen is lost by a chemical substance, it is called reduction. e.g., ZnO() s + C () s Zn () s + CO () g PbO + C Pb + CO Question 17. A shiny brown coloured element X on heating in air becomes black in colour. Name the element X and the black coloured compound formed. Shiny brown coloured substance is copper. It turns black on heating due to the formation of black coloured copper oxide. Cu + O CuO ( black) Copper (II) oxide

12 Hence, X = copper and compound formed is CuO (copper (II) oxide) Question 18. Why do we apply paint on iron articles? The corrosion of iron is called rusting. Rusting results in wastage of metal. Rusting occurs when (i) moisture and (ii) air are present So, to prevent the exposure of iron articles to moist air, we can apply paint so that contact is cut off and they can be prevented from rusting. In this way the surface gets protected against rusting. Question 19. Oil and fat containing food items are flushed with nitrogen. Why? Oil and fat containing food items when exposed to oxygen of air, get oxidised to form compounds that change the taste and smell of these food stuffs making them rancid. Flushing these food items with nitrogen which is an inert gas protects the food items from getting rancid. The Lays chips that you eat has nitrogen gas flushed in it to prevent rancidity. Question 0. Explain the following terms with one example of each. (a) Corrosion (b) Rancidity (a) Corrosion The process of slow degradation or eating up of metals when exposed to moist air is called corrosion. When a metal is attacked by substances around it such as moisture and acids etc., it is said to corrode and the process is called corrosion. eg.., the black coating on silver and the green coating on copper are other examples of corrosion. Silver develops black coat due to hydrogen sulphide of air. Ag + HS AgS + H (b) Rancidity When fats and oils are oxidised, they become rancid and their smell and taste get changed. Usually substances which prevent oxidation (antioxidants) are added to foods containing fats and oils. Keeping food in air tight containers helps to slow down oxidation. This is the reason why chips which we eat are usually flushed with nitrogen gas to prevent rancidity.

### Chapter 1 Chemical Reactions & Equations

CBSE Class 10th NCERT Science Chapter 1 Chemical Reactions & Equations Intext Questions On Page 6 Question 1: Why should a magnesium ribbon be cleaned before burning in air? Magnesium is an extremely reactive

### Chemical Reactions and Equations

Chemical Reactions and Equations Question 1: Why should a magnesium ribbon be cleaned before burning in air? Magnesium is very reactive metal. When stored it reacts with oxygen to form a layer magnesium

### NCERT Solutions. 95% Top Results. 12,00,000+ Hours of LIVE Learning. 1,00,000+ Happy Students. About Vedantu. Awesome Master Teachers

Downloaded from Vedantu NCERT Solutions About Vedantu Vedantu is India s biggest LIVE online teaching platform with over 450+ best teachers from across the country. Every week we are coming up with awesome

### Class X. Exercises solution

Exercises solution Question 1: Which of the statements about the reaction below are incorrect? Lead is getting reduced. Carbon dioxide is getting oxidised. Carbon is getting oxidised. Lead oxide is getting

### Website: Page 1. Page 14»Exercise» Page 15» Question 1:

Page 14»Exercise» Question 1: Which of the statements about the reaction below are incorrect? (a) Lead is getting reduced. (b) Carbon dioxide is getting oxidised. (c) Carbon is getting oxidised. (d) Lead

### LLT Education Services

Rahul Arora 18. What chemical reaction is involved in the corrosion of iron? 19. Aluminum metal when burnt in air forms aluminium oxide. Write the balanced chemical equation for the reaction. 20. Is the

### CHEMICAL REACTIONS & EQUATIONS

CHEMICAL REACTIONS & EQUATIONS PHYSICAL AND CHEMICAL CHANGE In our daily life many processes occur around us. Some of them do not lead to formation of any new substance, while others may lead to formation

CHAPTER No. 1 CHEMICAL REACTIONS AND EQUATIONS HOTS: (High Order Thinking Skill) Questions with Answers: 1 A compound `X` is used for drinking, has ph =7.Its acidified solution undergoes decomposition

TERM I CHAPTER 1- CHEMICAL REACTIONS AND EQUATIONS 1. During chemical reactions, chemical composition of substances changes or new substances are formed. 2.Chemical reactions can be written in chemical

### Chemical Reactions and Equations

Chemical Reactions and Equations 5-1 5.1 What is a Chemical Reaction? A chemical reaction is a chemical change. A chemical reaction occurs when one or more substances is converted into one or more new

### Balancing Equations Notes

. Unit 6 Chemical Equations and Reactions What is a Chemical Equation? A Chemical Equation is a written representation of the process that occurs in a chemical reaction. A chemical equation is written

### Balancing Equations Notes

. Unit 9 Chemical Equations and Reactions What is a Chemical Equation? A Chemical Equation is a written representation of the process that occurs in a chemical reaction. A chemical equation is written

### CHAPTER 8 SALTS. NaCl. A salt is an ionic substance produced when the hydrogen ion of the acid is replaced by metal ion or an ammonium ion.

CHAPTER 8 SALTS A salt is an ionic substance produced when the hydrogen ion of the acid is replaced by metal ion or an ammonium ion. The salt consists of two parts, cation from base and anion from acid.

### 8 Chemical Equations. Flames and sparks result when aluminum foil is dropped into liquid bromine.

8 Chemical Equations Flames and sparks result when aluminum foil is dropped into liquid bromine. Chapter Outline 8.1 The Chemical Equation 8.2 Writing and Balancing Chemical Equations 8.3 Types of Chemical

### Chemical Reactions and Equations

1 Chemical Reactions and Equations SYLLABUS Chemical reactions: Chemical equation, balanced chemical equation, implications of a balanced chemical equation. Types of chemical reactions: combination, decomposition,

### Chemical Reactions and Equations

Facts are not science as the dictionary is not literature. Martin H. Fischer CHAPTER 1 Chemical Reactions and Equations Consider the following situations of daily life and think what happens when milk

### Chemical Reactions Unit

Name: Hour: Teacher: ROZEMA / Chemistry Chemical Reactions Unit 1 P a g e 2 P a g e 3 P a g e 4 P a g e 5 P a g e 6 P a g e Chemistry Balancing Equations Balance the following equations by inserting the

### SCIENCE JSUNIL TUTORIAL CLASS 9. Activity 1

Activity Objective To understand, that there is a change in mass when a chemical change takes place. (To understand law of conservation of mass experimentally). Procedure. Take one of the following sets,

### CHAPTER Describing Chemical Reactions Reactants Products. New substances produced The arrow means yields TYPES OF EQUATIONS.

CHAPTER 11 Chemical Reactions 11.1 Describing Chemical Reactions Reactants Products New substances produced The arrow means yields Where do Chemical Reactions occur? Everywhere!!! In living organisms In

### Balancing CHEMICAL EQUATIONS

Balancing CHEMICAL EQUATIONS CHEMICAL REACTIONS involves a chemical change in the identity of one or more chemical species Ex. Rusting of iron (Fe): chemical rxn btwn water and iron involve the breaking

### 2. Relative molecular mass, M r - The relative molecular mass of a molecule is the average mass of the one molecule when compared with

Chapter 3: Chemical Formulae and Equations 1. Relative atomic mass, A r - The relative atomic mass of an element is the average mass of one atom of an element when compared with mass of an atom of carbon-12

### Reaction Writing Sheet #1 Key

Reaction Writing Sheet #1 Key Write and balance each of the following reactions and indicate the reaction type(s) present: 1. zinc + sulfur zinc sulfide 8 Zn (s) + S 8 (s) 8 ZnS (s) synthesis 2. potassium

### CHEMICAL REACTIONS. Types of Reactions. Steps to Writing Reactions

Types of Reactions CHEMICAL REACTIONS There are five types of chemical reactions we will talk about: 1. Synthesis reactions 2. reactions 3. Single displacement reactions 4. reactions 5. Combustion reactions

### Year 10 Chemistry Exam June 2011 Multiple Choice. Section A Mulltiple Choice

Year 10 Chemistry Exam June 2011 Multiple Choice Section A Mulltiple Choice 1. An aqueous solution is obtained when: a. a substance dissolves in any liquid b. a substance is dissolved in water c. when

### Indicators of chemical reactions

Indicators of chemical reactions Emission of light or heat Formation of a gas Formation of a precipitate Color change Emission of odor All chemical reactions: have two parts Reactants - the substances

### Unit 1 - Foundations of Chemistry

Unit 1 - Foundations of Chemistry Chapter 2 - Chemical Reactions Unit 1 - Foundations of Chemistry 1 / 42 2.1 - Chemical Equations Physical and Chemical Changes Physical change: A substance changes its

### Chemistry. Bridging the Gap Summer Homework. Name..

Chemistry Bridging the Gap Summer Homework Name.. Standard Form Number Number in standard form 0.008 8 x 10-3 0.07 7 x 10-2 0.55 5.5 x 10-1 0.000052 0.048 0.0086 0.00086 0.000086 0.0000000001 0.000455

### Science NCERT Exemplar Solutions Chapter 1: Chemical Reactions and Equations

Science NCERT Exemplar Solutions Chapter 1: Chemical Reactions and Equations Multiple Choice Questions (MCQs) Q. 1 Which of the following is not a physical change? (a) Boiling of water to give water vapour

### Representing Chemical Change

Representing Chemical Change As we have already mentioned, a number of changes can occur when elements react with one another. These changes may either be physical or chemical. One way of representing

### C2.6 Quantitative Chemistry Foundation

C2.6 Quantitative Chemistry Foundation 1. Relative masses Use the periodic table to find the relative masses of the elements below. (Hint: The top number in each element box) Hydrogen Carbon Nitrogen Oxygen

### Chemical Reactions. Chemical changes are occurring around us all the time

Chemical changes are occurring around us all the time Food cooking Fuel being burned in a car s engine Oxygen being used in the human body The starting materials are called reactants The ending materials

### Chemical Reactions. Ch. 11 Chemical Reactions. Chemical Reactions. Chemical Reactions

Chemical Reactions Ch. 11 Chemical Reactions when a substance changes identity Reactants - original Products - resulting law of conservation of mass total mass of reactants = total mass of products In

### Unit Learning Targets (L.T.):

Unit 9: Chemical Equations and Reactions Chapters 8 and 19 Name Block Unit Learning Targets (L.T.): By the end of the unit, students will be able to: Chapter 8: 1. Correctly write and balance chemical

### BALANCING EQUATIONS NOTES

BALANCING EQUATIONS NOTES WHY DO WE NEED TO BALANCE CHEMICAL EQUATIONS? The LAW OF CONSERVATION OF MASS says that matter cannot be created or destroyed. In other words, you cannot end up with any more

### Balancing Equations Notes

. Unit 7 Chemical Equations and Reactions What is a Chemical Equation? A is a written representation of the process that occurs in a chemical reaction. A chemical equation is written with the (starting

### Question 8 Chemical properties of metals and nonmetals. 1) magnesium 2) sulfur trioxide 3) iron (II) hydroxide 4) sodium nitrate

Question 8 Chemical properties of metals and nonmetals 1. Calcium oxide doesn t react with 1) NaNO 3 2) HCl 3) CO 2 4) H 2 O 2. Calcium oxide reacts with both of the following 1) SO 2 and O 2 2) H 2 O

### 9-1 The Nature of Chemical Reactions

9-1 The Nature of Chemical Reactions What are chemical reactions and why do they occur? A chemical reaction is a process in which one or more substances are converted into new substances with different

### Ch 7 Chemical Reactions Study Guide Accelerated Chemistry SCANTRON

Ch 7 Chemical Reactions Study Guide Accelerated Chemistry SCANTRON Name /80 TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. Correct the False statments by changing the

### CHEMISTRY PAPER 1999

CHEMISTRY PAPER 1999 (One and a half hours) Answers to this paper must be written on the paper provided separately. You will NOT be allowed to write during the first 15 minutes. This time is to be spent

### Lesson (1) Mole and chemical equation

Lesson (1) Mole and chemical equation 1 When oxygen gas reacts with magnesium, magnesium oxide is formed. Such Reactions are described by balanced equations known as "chemical equations" Δ 2Mg(s) + O2(g)

### Balancing Equations Notes

. Unit 9 Chemical Equations and Reactions What is a Chemical Equation? A is a written representation of the process that occurs in a chemical reaction. A chemical equation is written with the (starting

### Chemical reactions: Chemical reactions change substances into other substances.

Chemical reactions: Chemical reactions change substances into other substances. A chemical equation is used to represent a reaction. This has the form: reactants à products Word equations use the names

### UNIT 9 - STOICHIOMETRY

General Stoichiometry Notes STOICHIOMETRY: tells relative amts of reactants & products in a chemical reaction Given an amount of a substance involved in a chemical reaction, we can figure out the amount

### Types of Chemical Reactions (rxns.)

Types of Chemical Reactions (rxns.) Introduction Chemical reactions occur when bonds (between the electrons of atoms) are formed or broken Chemical reactions involve changes in the chemical composition

### THE ST. MICHAEL SCHOOL THIRD FORM CHEMISTRY MANUAL 3 SYMBOLS AND FORMULAE, CHEMICAL BONDING AND CHEMICAL EQUATIONS

1 THE ST. MICHAEL SCHOOL THIRD FORM CHEMISTRY MANUAL 3 SYMBOLS AND FORMULAE, CHEMICAL BONDING AND CHEMICAL EQUATIONS COMPILED BY G.WALKER, L.WORRELL, T. HARDING REFERENCE BOOKS Anne Tindale Chemistry A

### Chemical Equations and Chemical Reactions

Chemical Equations Chemical Equations and Chemical Reactions Chemical equations are concise representations of chemical reactions. Chemical Equations Symbols Used in Chemical Equations The formulas of

### Chemical Bonds In elements and compounds, the atoms are held together by chemical bonds.

Chemical Bonds In elements and compounds, the atoms are held together by chemical bonds. Forming a bond makes an atom more stable, so atoms form as many bonds are they are able to. Bonds are made using

### 2. Indicators of Chemical Rxns. Abbreviations of State (g) gas (l) liquid (s) solid (aq) aqueous a substance dissolved in water

Unit 6 Chemical Reactions 1. Parts of a Chemical Reaction 2. Indicators of a Chemical Reaction 3. Enthalpy 4. Balancing Chemical Equations 5. Word Equations 6. Classifying Chemical Reactions 7. Predicting

### CHEMICAL EQUATIONS WHAT BALANCING AN EQUATION MEANS

17 CHEMICAL EQUATIONS WHAT BALANCING AN EQUATION MEANS WHAT IS A CHEMICAL EQUATION? A chemical equation is a way of representing a chemical reaction in symbolic form. For example, when hydrochloric acid

### CHEMICAL REACTIONS. Introduction. Chemical Equations

CHEMICAL REACTIONS Chemistry I Chapter 7 1 Chemical Equations Their Job: Depict the kind of reactants and products and their relative amounts in a reaction. 4 Al (s) + 3 O 2 (g) ---> 2 Al 2 O 3 (s) The

### Jeddah Knowledge International School

Jeddah Knowledge International School Science Revision Pack 2016-2017 Quarter 1 Grade 9 Name: Section: Science Revision Pack Grade Nine Quarter One Page 1 Revision Pack Grade 9 Chemistry Question 1: Circle

### Year 10 Chemistry Exam June 2011 Multiple Choice. Section A Multiple Choice

Year 10 Chemistry Exam June 2011 Multiple Choice Section A Multiple Choice 1 An aqueous solution is obtained when: a. a substance dissolves in any liquid b. a substance is dissolved in water c. when a

### Chapter 8. Chemical Equations. Flames and sparks result when aluminum foil is dropped Into liquid bromine.

Chapter 8 Chemical Equations Flames and sparks result when aluminum foil is dropped Into liquid bromine. Introduction to General, Organic, and Biochemistry 10e John Wiley & Sons, Inc Morris Hein, Scott

### Chapter 7 - Chemical Reactions

Chapter 7 - Chemical Reactions Evidence of a Chemical Reaction If we could see the atoms and molecules that compose matter, we could easily identify a chemical reaction: Atoms combine with other atoms

### Introduction to Chemical Reactions. Making new substances

Introduction to Chemical Reactions Making new substances Main Ideas Chemical Reactions are represented by Chemical Equations. Chemical Equations are balanced to show the same number of atoms of each element

### Chemical Reactions. Burlingame High School Chemistry 1

Chemical Reactions 1 Chemical Equations Chemical equations are use to describe: the substances that react, the reactants the substances that are formed, the products the relative amounts of all substances

### Unit 11 Reactivity of metals

Unit 11 Reactivity of metals Comparing the reactivity of metals In unit 4, you learned that different extraction methods are used in the extractions of metals. Some metals, like silver and gold can exist

### A-LEVEL TRANSITION COURSE SUMMER 2018 PART 2: USING CHEMICAL EQUATIONS

A-LEVEL TRANSITION COURSE SUMMER 2018 PART 2: USING CHEMICAL EQUATIONS MASS AQUEOUS VOLUME ` MOLAR MASS GASEOUS VOLUME MOLES CONCENTRATION REVISION FROM LESSON 1 How many moles? 1) Jahin weighs a sample

### 11-1 Notes. Chemical Reactions

11-1 Notes Chemical Reactions Chemical Reactions In a chemical reaction 1 or more substances (the reactants) change into 1 or more new substances (the products). Reactants are always written on the left

### C2.6 Quantitative Chemistry Foundation

C2.6 Quantitative Chemistry Foundation 1. Relative masses Use the periodic table to find the relative masses of the elements below. (Hint: The top number in each element box) Hydrogen Carbon Nitrogen Oxygen

### Unit 5. Chemical reactions

Unit 5. Chemical reactions Index 1.- Physical and chemical phenomena...2 2.- What is a chemical reaction?...2 2.1. Chemical equation...2 2.2.- Balance of chemical reactions. Law of conservation of mass...3

### Unit 4: Reactions and Stoichiometry

Unit 4: Reactions and Stoichiometry Reactions Chemical equation Expression representing a chemical reaction Formulas of reactants on the left side Formulas of products on the right side Arrow(s) connect(s)

### Chapter 7. Chemical Reactions

Chapter 7 Chemical Reactions 1 All chemical reactions have two parts Reactants - the substances you start with Products- the substances you end up with The reactants turn into the products. Reactants Products

### Unit 5: Chemical Equations and Reactions & Stoichiometry

pg. 10 Unit 5: Chemical Equations and Reactions & Stoichiometry Chapter 8: Chemical Equations and Reactions 8.1: Describing Chemical Reactions Selected Chemistry Assignment Answers (Section Review on pg.

### CHAPTER 8 CHEMICAL REACTIONS AND EQUATIONS

CHAPTER 8 CHEMICAL REACTIONS AND EQUATIONS CHEMICAL REACTIONS Occurs when matter combines or breaks apart to produce new kinds of matter with different properties with a change in energy. EVIDENCE FOR

### Unit IV: Chemical Equations & Stoichiometry

Unit IV: Chemical Equations & Stoichiometry A. The chemical equation B. Types of chemical reactions A. Activity series of metals B. Solubility rules C. Rules for writing and balancing equations D. Calculations

### AS TRANSITION COURSE SUMMER 2016 onwards PART 2: USING CHEMICAL EQUATIONS

AS TRANSITION COURSE SUMMER 2016 onwards PART 2: USING CHEMICAL EQUATIONS MASS AQUEOUS VOLUME ` MOLAR MASS GASEOUS VOLUME MOLES CONCENTRATION REVISION FROM LESSON 1 How many moles? 1) Jahin weighs a sample

### Types of Reactions. There are five types of chemical reactions we observed in the lab:

Chemical Reactions Acids and Bases Acids: Form hydrogen ions (H + ) when dissolved in water. HCl (aq) H + (aq) + Cl - (aq) Examples: HCl (hydrochloric acid), HNO 3 (nitric acid), H 2 SO 4 (sulfuric acid),

### Funsheet 3.0 [WRITING & BALANCING EQUATIONS] Gu/R. 2017

Funsheet 3.0 [WRITING & BALANCING EQUATIONS] Gu/R. 2017 Balance the following chemical equations. Remember, it is not necessary to write "1" if the coefficient is one. 1. N 2 + H 2 NH 3 2. KClO 3 KCl +

### Acid, Bases and Salts (IGCSE Chemistry Syllabus )

Acid, Bases and Salts (IGCSE Chemistry Syllabus 2016-2018) Acid o A compound when dissolved in water produces hydrogen ions (H + ) ; proton (H + ) donor o It turns blue damp litmus paper to red o ph 1

### Chemical Reactions. Chemical Reactions Chemical reactions have a standard format when written:

0.3.notebook A chemical property is a behaviour that occurs when substances change to create a new substance. When a new substance is created, a chemical change has occurred. New colour Evidence of chemical

### Types of Reactions. There are five main types of chemical reactions we will talk about:

Chemical Reactions Types of Reactions There are five main types of chemical reactions we will talk about: 1. Synthesis reactions 2. Decomposition reactions 3. Single displacement reactions 4. Double displacement

### THE MOLE - PART 2. Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.

THE MOLE - PART 2 Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Which one of the following statements is a quantitative observation? a.

### 1. Parts of Chemical Reactions. 2 H 2 (g) + O 2 (g) 2 H 2 O(g) How to read a chemical equation

Unit 6 Chemical Reactions 1. Parts of a Chemical Reaction 2. Indicators of a Chemical Reaction 3. Enthalpy 4. Balancing Chemical Equations 5. Word Equations 6. Classifying Chemical Reactions 7. Predicting

### Chem A Ch. 9 Practice Test

Name: Class: Date: Chem A Ch. 9 Practice Test Matching Match each item with the correct statement below. a. product d. balanced equation b. reactant e. skeleton equation c. chemical equation 1. a new substance

### Question 1: Solution 1:

Book Name: Selina Concise Question 1: Comment, sulphuric acid is referred to as: (a) King of chemicals (b) Oil of vitriol Solution 1: (a) Sulphuric acid is called King of Chemicals because there is no

### From Writing Formulas to Balancing Equations A Tutorial

Chemistry Revised 2013 Name From Writing Formulas to Balancing Equations A Tutorial Period Oxidation Numbers. The Oxidation numbers written as s _ tell whether an element or group of elements lost or gained

### Identify the reaction type, predict the products, and balance the equations. If it is a special decomposition or synthesis, identify which kind.

Identify the reaction type, predict the products, and balance the equations. If it is a special decomposition or synthesis, identify which kind. 1. calcium + oxygen 2. cupric carbonate 3. aluminum + hydrochloric

### Various Types of Reactions

Various Types of Reactions Matthew Park Outline: 1. Synthesis / Replacement / Decomposition Reactions 2. Precipitation Reactions 3. Acid-Base Reactions 4. Summary: Metathesis Reactions NOTE: Not all of

### SCHOOL YEAR CH- 19 OXIDATION-REDUCTION REACTIONS SUBJECT: CHEMISTRY GRADE: 12

SCHOOL YEAR 2017-18 NAME: CH- 19 OXIDATION-REDUCTION REACTIONS SUBJECT: CHEMISTRY GRADE: 12 TEST A Choose the best answer from the options that follow each question. 1. During oxidation, one or more electrons

### CHEMICAL REACTION. Engr. Yvonne Ligaya F. Musico 1

CHEMICAL REACTION Engr. Yvonne Ligaya F. Musico 1 Chemical Reaction Engr. Yvonne Ligaya F. Musico 2 Introduction Chemical reactions occur when bonds between the outermost parts of atoms are formed or broken

### Symbols. Table 1 A set of common elements, their symbols and physical state

Symbols Symbols are a kind of shorthand system for writing down elements and compounds. Each element has a particular one or two letter symbol. The first letter of a symbol is always capital, and if there

### (DO NOT WRITE ON THIS TEST)

Final Prep Chap 8&9 (DO NOT WRITE ON THIS TEST) Multiple Choice Identify the choice that best completes the statement or answers the question. 1. After the correct formula for a reactant in an equation

### CHEMICAL REACTIONS WORDS, SYMBOLS AND ABBREVIATIONS

CHEMICAL REACTIONS All chemical reactions have two parts: (1) A substance that undergoes a reaction is called a. In other words, reactants are the substances you start with. (2) When reactants undergo

### Chapter 3 Chemical Reactions and Equations

Chapter 3 Chemical Reactions and Equations Chemical Reactions Reactions involve rearrangement and exchange of atoms to produce new pure substances. Reactants Products Chemical Equations Shorthand way

### ICP Final Exam Review - Part 2

ICP Final Exam Review - Part 2 Modified True/False Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true. 1. A combustion reaction occurs

### ICSE QUESTION PAPER Class X Chemistry (2016) Solution

ICSE QUESTION PAPER Class X Chemistry (016) Solution Section I 1. Metals are good reducing agents because they are electron donors. Electrovalent compounds have high melting points. (iii) Higher the ph

### Questions Booklet. UNIT 1: Principles & Applications of Science I CHEMISTRY SECTION. Level 3 Applied Science. Name:.. Teacher:..

Level 3 Applied Science UNIT 1: Principles & Applications of Science I CHEMISTRY SECTION Questions Booklet Name:.. Teacher:.. Level 3 Applied Science 2017-2018 Unit 1 (Chemistry) 1 1. State the relative

### CHEMICAL REACTIONS. The process by which one or more substances are changed into one or more different substances

CHEMICAL REACTIONS The process by which one or more substances are changed into one or more different substances Equations Reactions are represented by a chemical equation Reactants Products Must have

### Unit 8 Chemical Reactions- Funsheets

Part A- Balancing Equations and Types of Reactions Balance AND identify the following reactions: Unit 8 Chemical Reactions- Funsheets 1) Mg + Zn(NO 3) 2 Zn Mg(NO 3) 2 2) Ba + AgNO 3 Ag + Ba(NO 3) 2 3)

### CHEMISTRY REFERENCE STUDY MATERIAL. for CLASS X CHAPTER WISE CONCEPTS, FORMULAS AND QUESTIONS INLCUDING HOTS QUESTIONS.

CHEMISTRY REFERENCE STUDY MATERIAL for CLASS X 2017 18 CHAPTER WISE CONCEPTS, FORMULAS AND QUESTIONS INLCUDING HOTS QUESTIONS Prepared by M. S. KUMARSWAMY, TGT(MATHS) M. Sc. Gold Medallist (Elect.), B.

### Phase Changes: A type of Physical Change

Chemistry Ms. Ye Name Date Block Changes we observe about matter can be categorized as either a physical or chemical change: Physical Change: a change in which the Chemical Change: a change in which the

### Chemical Reactions. All chemical reactions can be written as chemical equations.

Chemical Reactions All chemical reactions can be written as chemical equations. What is a Chemical Reaction? Chemical reactions represent chemical changes A chemical change occurs when a substance has

### General Stoichiometry Notes STOICHIOMETRY: tells relative amts of reactants & products in a chemical reaction

General Stoichiometry Notes STOICHIOMETRY: tells relative amts of reactants & products in a chemical reaction Given an amount of a substance involved in a chemical reaction, we can figure out the amount

### Chapter 8 Chemical Reactions

Chemistry/ PEP Name: Date: Chapter 8 Chemical Reactions Chapter 8: 1 7, 9 18, 20, 21, 24 26, 29 31, 46, 55, 69 Practice Problems 1. Write a skeleton equation for each chemical reaction. Include the appropriate

### Chapter 8 Chemical Reactions

Chemistry/ PEP Name: Date: Chapter 8 Chemical Reactions Chapter 8: 1 7, 9 18, 20, 21, 24 26, 29 31, 46, 55, 69 Practice Problems 1. Write a skeleton equation for each chemical reaction. Include the appropriate

### CHEMISTRY 135 REVISION OF NAMES, FORMULAE AND EQUATIONS

CHEMISTRY 135 REVISION OF NAMES, FORMULAE AND EQUATIONS Answer the following questions as if you were going to hand them in for marking. You will be tested on them in class time. 1) Give the correct chemical

### CHEMISTRY. SCIENCE Paper 2. (Two hours) You will not be allowed to write during the first 15 minutes.

CLASS IX CHEMISTRY SCIENCE Paper 2 (Two hours) Answers to this Paper must be written on the paper provided separately. You will not be allowed to write during the first 15 minutes. This time is to be spent