1/31/2013 CHEMICAL EQUATIONS & REACTIONS NOTES. Write the formulas of the following compounds: 1. nickel (II) chloride. 2. copper (II) nitrate

Size: px

Start display at page:

Download "1/31/2013 CHEMICAL EQUATIONS & REACTIONS NOTES. Write the formulas of the following compounds: 1. nickel (II) chloride. 2. copper (II) nitrate"

Angela Suzanna Robinson
5 years ago
Views:

1 CEMICAL EQUATIONS & REACTIONS NOTES Ionic compounds can form from metals Transition metals do not always follow the patterns that we discussed Can have more than one oxidation number () To identify the charges of transition metals, roman numerals are placed in their name, directly after the transition metal The number of the roman numeral is equal to the I = II = III = IV = Examples: Iron (II) chloride Iron (III) oxide Fe -1 Fe O -2 You will need to be able to write the formulas of these compounds from their name On page 11, shade in the following metals in ORANGE and update your key Then write in their possible charges in each box 24 Chromium: +2, Manganese: +2, +3, Iron: +2, Cobalt: +2, Nickel: +2, Copper: +1, Zinc: Silver: Cadmium: Tin: +2, Gold: +1, Mercury: +1, Lead: +2, +4 Write the formulas of the following compounds: A change in the size, shape, state of matter, etc. that does not change the of a substance 1. nickel (II) chloride A phase change is a physical change even though energy may be removed or added to the substance 2. copper (II) nitrate 3. iron (III) hydroxide In the new state of mater, the substance is still made of the same components, the atoms just have more or less energy (phase changes are the only physical changes that have energy changes) 4. gold (I) oxide i.e. if liquid water evaporates, it becomes water vapor if water vapor condenses, it becomes liquid water 1

2 The change of one substance into a substance (chemical reaction) A chemical change alters the original chemical make-up of the substance changes and changes always accompany chemical changes ow can you tell if a chemical change has taken place? Evolution of heat, light, and/or sound (sometimes heat can be absorbed too) A gas is produced, bubbles (effervescence) When solid particles form from 2 liquids Unexpected Color change (i.e. clear liquid + clear liquid purple liquid) When energy flows of the system as heat, the process is. Usually feels Ex: Combustion of a match, hand warmers Processes that energy from the surroundings are. Usually feels Ex: Melting ice cubes, ice packs Reactants the substances that exist a chemical change (or reaction) takes place. Products the _ substance(s) that are formed the chemical changes. CEMICAL EQUATION a description of a chemical reaction that uses chemical and to indicate the reactants and products of a reaction. 2

+ (s) (l) (g) (aq),, or ; indicates result of reaction A reactant or product in the _state; also used to indicate a A reactant or product in the state A reactant or product in the state A reactant or

3 + (s) (l) (g) (aq),, or ; indicates result of reaction A reactant or product in the _state; also used to indicate a A reactant or product in the state A reactant or product in the state A reactant or product dissolved in (in an aqueous solution) 7 elements Molecules made out of 2 atoms ( di =, atomic = ) Some elements are never found alone and will always bond with another atom of the same type to become stable (O 2, N 2, 2, etc.) ydrogen and the other 6 elements form a 7 shape (nitrogen has an atomic number of 7) On page 11, shade these 7 elements in YELLOW and add to your key Write the equation for the reaction of methane gas (carbon tetrahydride) with oxygen to form carbon dioxide and water. + + Reactants Products Notes: Water will always be a, unless stated otherwise in the problem Oxygen is a diatomic molecule and will always be a Carbon dioxide will always be a, unless stated otherwise in the problem If the state of matter is not indicated in the word problem, always assume the element/compound is in it s _state at room temperature Write an equation for the reaction between chlorine and aqueous sodium bromide to produce bromine and aqueous sodium chloride. + _ _+ Notes: Chlorine and Bromine are a molecules Chlorine is normally a at room temperature Bromine is normally a at room temperature Write the equation for the reaction between solutions of aluminum sulfate and calcium chloride to form a white precipitate of calcium sulfate and aqueous aluminum chloride

Solid aluminum oxide is formed when aluminum metal reacts with oxygen. Write the equation for this reaction. + 4 Al (s) + 3 O 2(g) 2 Al 2 O 3(s) aluminum oxide The numbers in the front are called.

4 Solid aluminum oxide is formed when aluminum metal reacts with oxygen. Write the equation for this reaction. + 4 Al (s) + 3 O 2(g) 2 Al 2 O 3(s) aluminum oxide The numbers in the front are called. Coefficients apply only to the element or compound that comes directly AFTER it. Just like in math, a coefficient indicates that everything behind it is multiplied by that number 4 Al = aluminum atoms The numbers behind an atomic symbol are called Subscripts apply only to the element that comes directly BEFORE it If parenthesis come directly before the subscript, then the subscript is multiplied by everything within the parenthesis O 2 = oxygen atoms (O) 2 = oxygen atoms hydrogen atoms Coefficients and subscripts together multiply by both the coefficient and subscript 2(N 4 ) 2 = nitrogen atoms hydrogen atoms Chemical Symbol Meaning Composition 2 O 2 2 O 2 O 2 One molecule of water: Two molecules of water: One molecule of hydrogen peroxide: atoms and O atom atoms and O atoms atoms and O atoms Law of Conservation of Matter Matter is not lost in a chemical reaction- Atoms are just (Remember John Dalton?) The same atoms are present in a reaction at the beginning (reactants) and at the end (products) This means that when we write our chemical equations, we need to have the number of atoms on sides of the reaction arrow! Otherwise matter would not be conserved. Kotz web 4

5 2(g) + 2(g) (aq) (unbalanced) reactants products 2(g) + 2(g) (aq) (balanced) reactants products Balanced Equation one in which the number of atoms of each element as a reactant is to the number of atoms of that element as a product To balance equations, we add in front of the element/compound Do not change the subscripts because then you will change the compound! 1. Identify the most complex substance. 2. Beginning with that substance, choose an element that appears in only one reactant and one product. Adjust the coefficients to obtain the same number of atoms of this element on both sides. Balance polyatomic ions as a unit (if possible). Re-write 2 O as -O if hydroxide is present 3. Balance the remaining atoms End with the least-complex substance Leave single elements/diatomic molecules until last 4. Double check - Make sure that the atoms of each element are the same on both sides of the equation. C 4 (g) + O 2 (g) CO 2 (g) + 2 O (l) C = = O = 2 (g) + NaBr (aq) Br 2(g) + Na (aq) = Na = Br = C = = O = = Na = Br = 5

6 Al 2 (SO 4 ) 3(aq) + Ca 2(aq) CaSO 4(s) + Al 3(aq) Al = SO 4 = Ca = = Al = SO 4 = Ca = = (N 4 ) 3 PO 4 + Mg(O) 2 Mg 3 (PO 4 ) + 2 N 4 O Al 3 + Li 2 CO 3 Al 2 (CO 3 ) 3 + Li 6

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)