Mr. Rivas Chemistry Final Exam Extra Credit Review Packet 2015

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1 Mr. Rivas Chemistry Final Exam Extra Credit Review Packet 2015 Lab Equipment, Reports and Safety: Big Ideas: 1. Laboratory equipment has specific uses, and also limitations on their uses. 2. Each piece of equipment provides data with specific units. 3. Safety rules and procedures are designed to protect you from contact with chemicals and broken glass. Cuts from broken glass is one of the most common injuries in the chemistry lab. 4. Your eyes must always be protected with safety goggles. 1. Identify the following equipment. What is it used for? Could you identify it from a picture? a. Beaker b. Graduated cylinder c. Balance d. Goggles e. Erlenmeyer flask f. Beaker and Crucible Tongs g. Striker 2. Concepts & lab reports: Define the following. What are they used for? a. precipitate b. reference material (reference solution) c. control d. variable e. purpose f. hypothesis Page 1 of 17

2 g. data Water Unit: h. conclusion Big Ideas: 1. Chemists use the metric system when recording their measurements. 2. Dimensional analysis must be used to convert between measurement units. 3. Chemicals have both physical and chemical properties that can be used to tell them apart, and also to separate components of a mixture. 4. Water s polarity makes it an excellent solvent. 5. When it comes to evaluating a solute/solvent relationship, remember the phrase like dissolves like. 6. Solubility can be quantified with a solubility curve, and by calculating the % concentration of a solution. 7. An imbalance of H3O + and OH - ions causes solutions to be either acidic or basic. 1. Define the following mixtures. Give two real-life examples of each. How could you experimentally test for each? How would you separate the components? a. Solution b. Colloid c. Suspension 2. What is the Tyndall test? When would you use it? 3. Do the following conversions. Show your work. Indicate the type of measurement (distance, volume or mass) a. Convert 150 km to meters b. Convert 45 cl to ml c. Convert grams to mg d. Convert 60 ml to cm 3 Page 2 of 17

3 e. Convert 15 kg to mg 4. Calculate the density of an object that has a mass of g and occupies 24.7 cm What types of substances are removed from mixtures using filtration? Adsorption? Distillation? Think about the foul water lab! 6. Identify the following as physical or chemical property. a. density b. surface tension c. liquid at room temperature d. boiling point e. reacts with an acid to produce H 2 gas f. electrically conductive g. dissolves ionic compounds h. breaks down into H 2 (g) and O 2 (g) i. color j. inert 7. Draw and label a picture of a water molecule. Explain it in terms of being polar. Show hydrogen bonds between different water molecules. 8. Why does table salt (NaCl) dissolve in water but not cooking oil? 9. Define the following: solute, solvent and solution g of ethanol is dissolved in 115 g of water. What is the % concentration of ethanol? Page 3 of 17

4 11. How many grams of salt would be found in 15 grams of a 25% NaCl solution? Use the following two graphs to answer questions What mass of KNO 3 will dissolve in 100 g of water at 50 C? 13. What mass of KBr will dissolve in 100 g water at this temperature? g of KNO 3 is dissolved in 100 g of water at 30 C. Is this solution saturated, unsaturated or supersaturated? 15. In order to make this solution saturated, how much more KNO 3 must be added? 16. What is the minimum mass of water to dissolve 30 g KNO 3 at 30 C? 17. What mass of oxygen can be dissolved in 1000 g of water at 30 C? At 20 C? 18. What mass of oxygen can be dissolved in 100 g of water at 20 C? 19. Fill in the following table indicating if the substance would be soluble or insoluble. Polar Solvent Polar Solute Non-polar Solute Ionic solute Page 4 of 17

5 Non Polar Solvent 20. Identify each as an acid, base or neutral substance when dissolved in water. Indicate the ph (less than, greater than, or equal to 7) of the solution formed from this substance. a. NaBr b. HBr c. HNO 3 d. NaOH 21. If the concentration of H 3O + in a solution is 1 x 10-5, what is the ph? Resources Unit: Big Ideas: 1. Ionic compounds form when atoms gain or lose electrons. Metals lose electrons, nonmetals gain them. 2. The number of electrons gained or lost can be predicted with an understanding of the octet rule and the number of valence electrons an atom contains. 3. The periodic table is organized by electron configuration, and elements are classified as metals, nonmetals or metalloids based on physical and chemical properties. 4. Atoms have a central nucleus that contains the protons and neutrons, and electrons are found in orbitals located outside the nucleus. 5. Electron configurations are used to describe locations of electrons within levels, sublevels and orbitals. 6. Metal reactivity is summarized in the Metal Activity Series. 7. The quantity 6.02 x is called a mole, and the periodic table lists the mass of 1 mole of each element s atoms, called the molar mass of the element. 8. Conversions between moles, particles, and mass are widely used in chemistry. 1. An element is found that is a good conductor of electricity, is ductile, brittle and doesn t react with an acid. This element is best classified as a (metal / nonmetal / metalloid). 2. The current periodic table is arranged according to increasing. 3. Elements in the same vertical column are in the same or and have similar physical and chemical properties due to similar. Page 5 of 17

6 4. Estimate the boiling point of krypton if the bp of Ar is -186 C and that of Xe is -112 C. 5. Define: a. element b. cation c. anion d. ionic compound e. covalent compound 6. Fill in the following table: Name Symbol Atomic Number # protons # neutrons in most common isotope Electron configuration Atomic Mass Hydrogen Cu Of the following elements: Na Mg Li K a. Which element is in the fourth energy level? b. Which are in the same family/group? c. Which are in the same period? 8. Label the blank PT with s, p, d block locations metals/nonmetals/metalloids **where s the stairstep? valence electrons of elements within Groups I VIII. Predicted ion charges of elements within Groups I VIII. Page 6 of 17

7 9. Calculate the molar masses of each substance below. Round atomic masses to 1 decimal place. Chemical Molar Mass Particle name? SrCl2 OF2 Co(NO3)2 CO2 10. Complete the following table: NaF Element or compound? If a compound, ionic or covalent? Particle name? (atom, molecule or formula unit) Cl 2 H 2O LiCl Al CBr 4 NH 3 Ca(NO 3) 2 He C 3H Complete the following mole conversions. Show all your dimensional analysis work. a. How many moles are in 72.9 g of HCl? b. How many moles are in 11.2 L of CO 2 gas at STP? c. How many molecules are in 720 g of C 6H 12O 6? Page 7 of 17

8 d. How many grams are in 3.5 mol of Ca 3(PO 4) 2? e. What is the volume of 1.35 mol of Cl 2 gas at STP? f. How many formula units are in 85 g of AgNO 3? g. Convert g of LiBr to moles. h. Convert 2.5 g of CuCl 2 to moles. i. How many grams of lithium are there in 3.45 moles? j. How many moles of nitrogen are there in molecules? k. How many cadmium atoms are there in moles? l. How many grams of SO 2 are molecules? 12. Percent Composition. Calculate the percent composition (by mass) of each element in the following: a. C in CH 4 b. H in H 2O c. Ba in BaCO 3 Page 8 of 17

9 d. N in Cu(NO 3) Use the metal activity series to predict whether the following reactions will occur. If they do, write the products and then balance the equation. a. CuCl 2 + Al b. NaNO 3 + Zn c. LiCl + Ag d. K + Al 2(SO 4) Explain why this reaction is NOT an example of a Redox reaction. 2 NaNO 3 + BaI 2 Ba(NO 3) NaI 15. Complete the table below. Li +1 cation, anion or neutral atom? Number of electrons in substance S -2 Na 0 bromide ion magnesium ion 16. Which have a full octet? Choose all that apply. Na Xe F Na Complete the table below. Page 9 of 17

10 Name of element Metal, nonmetal or metalloid? How many valence electrons? Electron configuration Ca Se Zn F K Si Petroleum Unit: Big Ideas: 1. Carbon atoms make 4 bonds, and can arrange these bonds by using single, double, or triple bonds to other atoms. 2. Electron-dot and structural formulas describe the bonds between atoms in alkanes, alkenes and alkynes. 3. Petroleum is a nonrenewable resource, and many everyday materials are produced from petrochemical starting materials. Fractional distillation is used to separates the fractions (components) of petroleum. 4. Compounds can be isomers if they have the same molecular formula, but different structural formulas. 5. Hydrocarbons can be evaluated as possible fuel sources by examining their heats of combustion. 6. Energy values can be inserted into a balanced chemical equation. 7. The specific heat of a substance is a measure of its resistance to temperature change. Energy gained or lost = (mass) (specific heat constant) (change in temperature) 8. Functional groups are the reactivity centers of hydrocarbon molecules. 1. Draw the electron-dot structure for the following compounds: a. C 2H 6 Page 10 of 17

b. C 2H 4 c. CH 4 d. C 2H 4Cl 2 (there are two isomers of this try to draw both!) 2. Draw two isomers of C 6H 14. 3. Draw and name the alkane, alkene and alkyne with three carbons. 4. Which is saturated: C 2H 4 or C 2H 6?

11 b. C 2H 4 c. CH 4 d. C 2H 4Cl 2 (there are two isomers of this try to draw both!) 2. Draw two isomers of C 6H Draw and name the alkane, alkene and alkyne with three carbons. 4. Which is saturated: C 2H 4 or C 2H 6? Why? 5. Using the molar heats of combustion table, write thermochemical equations for the combustion of: a. methane b. butane c. octane 6. Using the molar heats of combustion table, calculate the energy released from the burning of: a. 3 mol C 2H 6 b. 24 grams methane c. 5.4 x molecules C 4H 10 Page 11 of 17

12 7. The specific heat of water is 4.2 J/g C. How many joules are absorbed if 10 g of water is heated from 25 C to 37 C? Chemical Reactions Unit: Big Ideas: 1. Chemical reactions must be balanced with coefficients to obey the law of conservation of mass/atoms. 2. Coefficients are interpreted as either particle, mole, or (if everything is a gas) liter ratios. 3. Stoichiometry is the name given to the process of using coefficients as mole ratios to convert between chemicals in a reaction equation. How much is used? How much is made? These questions can be answered with a stoichiometric calculation. 1. List three ways that coefficients can be interpreted in a chemical reaction. 2. What are the seven diatomic elements? How can you remember them? 3. Identify products, reactants, coefficients, and subscripts in the following equations: a. Ca (s) + 2 H 2O (l) Ca(OH) 2 (aq) + H 2 (g) b. 6 H 2O + 4 NO 4 NH O 2 4. Write the formulas for the compounds formed between the element or ion pairs listed below: Remember balance the charges! magnesium and sulfide barium and iodide Page 12 of 17

13 aluminum and carbonate ion lead(iv) and sulfate sodium and chloride lithium and hydroxide beryllium and hydroxide iron(iii) and nitride ammonium and phosphate ions 5. Balance the following equations. a. S 8 + O 2 SO 3 b. N 2 + O 2 N 2O c. HgO Hg + O 2 d. CO 2 + H 2O C 6H 12O 6 + O 2 e. SiCl 4 + H 2O H 4SiO 4 + HCl f. Na 2CO 3 + HCl NaCl + H 2O + CO 2 g. Na + H 2O NaOH + H 2 6. Transform these word equations into balanced chemical equations. a. Aluminum sulfate + Calcium hydroxide Aluminum hydroxide + Calcium sulfate b. Aluminum + Hydrogen chloride Aluminum chloride + Hydrogen gas c. Lead(II) nitrate Lead(II) oxide + Nitrogen dioxide + Oxygen gas Stoichiometry Problems. Show all the dimensional analysis work! 7. Consider the reaction: 4 NH 3 (g) + 5 O 2 (g) 6 H 2O (g) + 4 NO (g) a. How many moles of NO (g) are produced from 2.00 mol of NH 3 (g)? Page 13 of 17

14 b. How many grams of H 2O (g) is produced from 4.00 mol of O 2 (g)? c. How many liters of NH 3 (g) is required to react with 3.00 liters of O 2 (g)? 8. How many grams of silver chloride can be produced from 34.0 grams of silver nitrate according to the reaction below? AgNO 3 + CuCl 2 AgCl + Cu(NO 3) 2 9. Chlorine gas reacts with sodium metal to produce sodium chloride. What mass of Chlorine will be needed to react with 12.3 g of sodium? Cl 2 + Na NaCl 10. Aluminum metal reacts with a solution of copper(ii) nitrate. If you want to produce 5.4 x atoms of copper, how many moles of aluminum metal are needed? Al + Cu(NO 3) 2 Cu + Al(NO 3) Limiting Reactants a. How do limiting reactant problems look different from regular stoichiometry problems? b. Our bodies burn sugar, forming water and carbon dioxide as follows: Page 14 of 17

15 1 C 6H 12O O 2 6 H 2O + 6 CO 2 If your body takes in 20 moles of O 2 from the air, and you eat 45 moles of sugar, which is the limiting reactant? c. Using the same reaction equation, how many grams of CO 2 can be produced from the reaction of 15 grams of sugar and 25 grams of oxygen? Gaes Unit: Big Ideas: 1. 4 variables describe a gas behavior: P, V, n and T. 2. Boyle, Charles and Gay-Lussac developed mathematical gas laws that are used to predict and calculate changes in gas properties. 3. At STP, one mole of any gas occupies a volume of 22.4 L. This is called the molar volume of a gas. 1. If a balloon changes its volume from 2 L to 12 L, how would the Kelvin temperature of the gas in the balloon change? Give a numerical answer. What gas law applies here? 2. What are the conditions of temperature and pressure that scientists call STP conditions? 3. Write the equations for Boyle s Law, Charles Law, Gay-Lussac s law, and the Combined gas law. 4. A gas has a volume of 350 ml at 23 C. What is the new volume of the gas, if the temperature is dropped to 5 C? Page 15 of 17

16 Which gas law applies here? 5. A balloon contains argon gas at a pressure of kpa and 29 C. Calculate the new temperature of the gas, if the volume is held constant, but the pressure is reduced to 99.4 kpa. Which gas law applies here? 6. A bicycle tire is filled with 425 ml of air, until the pressure is 1.35 atm. If 200 ml of air is added to the tire, what will be the new pressure? Which gas law applies here? 7. A weather balloon has a volume of 18 L at STP conditions. Soon after, the pressure changes to 0.75 atm and the volume increases to 25 L. What is the new Kelvin temperature of the gas? Which gas law applies here? 8. A container of nitrogen gas is at 150 C, and a pressure of kpa. Without changing the volume of the gas, what will the Celsius temperature of the gas be if the pressure is changed to 25.4 kpa? Page 16 of 17

17 Which gas law applies here? 9. A sample of helium gas with an unknown volume is at 300 K and kpa. When the gas is placed in a container with a volume of 6.5 ml and a temperature of 125 K,, the pressure is measured as kpa. What was the original volume of the gas sample? Which gas law applies here? 10. Whenever you use a temperature value in a gas law equation, what unit must the temperature be in? How do you convert between Celsius and this temperature unit? 11. Convert 25 C to Kelvin. 12. Convert -120 C to Kelvin 13. What is room temperature in Celsius? In Kelvin? 14. What is the volume of one mole of any gas at STP conditions? 14. How many moles are in 18.6 L of CO gas at STP? Page 17 of 17

OPTIONAL PRACTICE PROBLEMS

OPTIONAL PRACTICE PROBLEMS 1 DIMENSIONAL ANALYSIS AND PROPERTIES OF MATTER (1) List the base (fundamental) SI units: (2) Fill in the following table: Object Weight, g Mass, g Piece of iron 50 g? Huge container