Review - 3rd Nine Weeks Exam.docx

Name _______________________________________________ Period ______ Date ____________________ Third Nine Weeks Exam Review Pre-AP Chemistry Chemical Reactions Review: This material will not be tested directly, but is a GREAT review!!! 1. List the indicators of a chemical change. 2. What does a balanced chemical equation describe? 3. Write the symbols for the following states of matter: solid, liquid, gas, and aqueous. What is the symbol for heating? 4. Write the chemical formulas for the 7 diatomic molecules. 5. What is a precipitate? How is one formed? What subscript symbol is used to represent one? 6. List and describe the 5 types of chemical reactions. 7. How does the Law of Conversation of Mass apply to chemical reactions? 8. Balance the following chemical equations and identify the type of reaction: a. ____2Li + ____2HCl  ____2LiCl + ____1H2 Type of reaction: b. ____NiSO4 + ____NaI  ____NiI2 + ____Na2SO4 Type of reaction: c. ____Al2O3  ____Al + ____O2 Type of reaction: d. ____C2H6 + ____ O2  ____H2O + ____CO2 Type of reaction: e. ____Mg + ____O2  ____MgO Type of reaction: 9. Write a balanced chemical equation for the following reactions and identify the type of reaction: a. When heated, solid potassium chlorate breaks down into solid potassium chloride and oxygen gas. 2 KClO3  2 KCL + 3 O2 b. Zinc metal is immersed in a weak solution of hydrochloric acid (HCl) to produce aqueous zinc (II) chloride and hydrogen gas. c. Gaseous ammonia (nitrogen trihydride) is synthesized from hydrogen gas and nitrogen gas. d. A solution of calcium chloride reacts with solid sodium carbonate to form solid calcium carbonate and sodium chloride dissolved in water. e. Solid glucose, C6H12O6, burns with excess oxygen gas. (Hint: what are the products of this type of reaction?) 10. What is an activity series and how is it used to predict the products of a single replacement reaction? 11. Predict the products for the following chemical reactions using the activity series or solubility rules chart. Write NR if no reaction occurs and include states of matter: a. Lead (II) solid reacts with zinc (II) chloride  b. Rb(s) + Zn(NO3)2(aq)  c. Cl2 + KI  d. AgNO3(aq) + NaCl(aq)  e. Aqueous lithium hydroxide reacts with iron (III) nitrate dissolved in water  f. Sodium carbonate + ammonium sulfide  Moles Review: 1. How many molecules would be in a 2.05 mole sample of carbon dioxide? 6.0*10^23 2. How many grams are in 4.5 moles of carbon? Times molar mass 3. Determine how many atoms are in 15.0 grams of Mg. 6.0*10^23 4. How many ions are present in a 52.5 gram sample of calcium chloride? 5. Write the empirical formulas for the following chemicals: g. C6H12O6 CH2O j. H2SO4 h. C4H8O4 CH2O k. H2O2 i. CH2O l. N2O2 6. Determine the percent composition of each element for the following chemicals: m. BaCl2 o. Ba(NO3)2 n. Copper (II) oxide p. Sodium Sulfate 7. A sample of brown gas, a major air pollutant, is found to contain 30.45% N and 69.55% O. Determine the empirical formula of the substance. 8. The empirical formula of butane gas, the fuel in Bic lighters, is C2H5. What is the molecular formula if the molar mass of butane is 58.14 g/mol?

9. Find the empirical and molecular formula of a substance that has a molar mass of 228.33 and contains 47.37% C, 10.59% H, and 42.04% O. 10. A sample of manganese(II) chloride has a mass of 5.00 grams before heating, and 3.89 grams after heating until all the water is driven out. Based on the given information, determine the formula and name of the hydrate. Stoichiometry Review: 1. What are the four types of stoichiometry problems? Describe the steps for solving each type of problem. 2. What is a mole ratio? Where do you find mole ratios? a. Write all of the unique mole ratios between the substances in the following reaction: 2 H2 + O2  2 H2O 3. What is the molar mass of a compound and how is it calculated? Give the units for molar mass. a. Find the molar mass of chlorine gas b. Find the molar mass of aluminum oxide 4. Define limiting reactant. If given two amounts of reactants, how do you determine which is the limiting reactant? 5. Define excess reactant. 6. How is percent yield calculated? 7. Describe “actual” yield and tell how you will know the value? 8. Describe “theoretical” yield and tell how you will know the value? 9. Which number should be larger, actual or theoretical yield? 10. ___ FeCl3 (aq) + ___ NaOH (aq)  ___ Fe(OH)3 (s) + ___ NaCl (aq) a. Balance the equation. b. What is the mole ratio of FeCl3 to NaOH? c. What is the mole ratio of FeCl3 to NaCl? d. Given 3.00 moles of NaOH and an excess amount of FeCl3, how many moles of NaCl can be produced? e. If 333 grams of Fe(OH)3 is produced, how many moles of NaOH were used? f. How many grams of NaOH are needed to react completely with 62.1 grams of FeCl3? 11. ____ Ba(OH)2 (aq) + ____ AlCl3 (aq)  ____ Al(OH)3 (s) + ____ BaCl2 (aq) Aqueous barium hydroxide and aqueous aluminum chloride react to form solid aluminum hydroxide and aqueous barium chloride in the unbalanced reaction above. 60.00 grams of aqueous barium hydroxide are added to 30.00 grams of aqueous aluminum chloride. 5.50 grams of the precipitate are actually produced. a. Balance the equation. b. What is the precipitate? c. How many grams of the precipitate can be theoretically produced? d. What is the limiting reactant? e. How much excess reactant is used up? Remains? f. What is the percent yield for the reaction? Gas Laws Review: 1. Real gases behave like ideal gases at _______ temperature and ________ pressure. 2. How is the temperature and average kinetic energy of a sample of gas related? 3. Specifically describe what causes pressure inside a container of gas. 4. What does Boyle’s Law describe? What is the formula for Boyle’s Law? a. How are the two variables related (directly or inversely proportional)? 5. What does Charles’s Law describe? What is the formula for Charles’s Law? a. How are the two variables related (directly or inversely proportional)? 6. What does Gay-Lussac’s Law describe? What is the formula for Gay-Lussac’s? a. How are the two variables related (directly or inversely proportional)? 7. Write the formula for the Combined Gas Law. 8. Describe Dalton’s Law of Partial Pressures. What is the formula? 9. STP stands for Standard Temperature and Pressure. a. What is standard temperature in oC? K? b. What is standard pressure in atm? mmHg? kPa? 10. Convert the following temperatures: a. 250. K = ________ oC c. -17.0 oC = ________K b. 0.00oC = ________ K d. 155 K = ________ oC

11. Convert 0.590 atm to the following = _____________ mmHg = ______________ kPa 12. Avogadro’s law states that equal amounts of gases at the same ________________ and _______________ have equal volumes. 13. The standard molar volume of any gas is _______ L. 14. What is the volume of 6.02 x 1023 gas molecules at 273K and 1 atm? 15. Describe and write the formula for the Ideal Gas Law as well as its molar mass and density variations. 16. Define the 5 variables of the Ideal Gas Law. Pv = nrt 17. What is ‘R’? What are the different values for ‘R’, and how do you know when to use a certain one? 18. Define and compare and contrast: effusion v. diffusion. 19. Describe Graham’s Law of effusion. How is this applied in reality? 20. How are molar mass and speeds of gases related? 21. Gas Law Calculations: Identify the Gas Law used and then solve. The volume of a gas is 6.00 L when the temperature is 10.0oC. If the gas is moved outside to where the temperature is –5.00oC, what volume will the balloon occupy? Gas Law ____________________________ b. How many moles of helium gas would it take to fill a gas balloon with a volume of 1000. mL when the temperature is 32 oC and the atmospheric pressure is 752 mmHg? Gas Law ____________________________ c. A 10.0 liter tank of sulfur gas is at a pressure of 3.0 atm. What volume of oxygen will be available if the sulfur is used at standard pressure? Gas Law ____________________________ d. How many moles of nitrogen gas will occupy a volume of 347 ml at 1020 mmHg and 27oC? e. If the pressure of a 345 ml sample of oxygen at 1.15 atm at constant temperature is reduced to 0.95 atm, what is the new volume? Gas Law ____________________________ f. Find the volume, in liters, of 8.00 grams of oxygen gas, O2, at STP. Gas Law ____________________________ g. Blast furnaces give off many unpleasant and unhealthy gases. If the total air pressure is 0.99 atm, the partial pressure of carbon dioxide is 0.050 atm, and the partial pressure of hydrogen sulfide is 0.020 atm, what is the partial pressure of the remaining air? Gas Law ____________________________ h. What volume will 2.0 moles of nitrogen occupy at STP? Gas Law ____________________________ i. A container holds 265 mL of chlorine gas. Assuming that the gas sample is at STP, what is its mass? Gas Law ____________________________ j. A sample of hydrogen effuses through a porous container about 9.0 times faster than an unknown gas. Estimate the molar mass of the unknown gas. Gas Law ____________________________ k. If a molecule of neon gas travels at an average of 400. m/s at a given temperature, estimate the average speed of a molecule of butane, C4H10, at the same temperature. Gas Law ____________________________ l. A gas sample that has a mass of 0.993 g occupies .570 L. Given that the temperature is 281 K and the pressure is 1.44 atm, what is the molar mass of the gas? Gas Law ____________________________ m. Find the volume of 3.01 x 1023 molecules of H2S gas at STP. Gas Law ____________________________ n. The three primary components of air are carbon dioxide, nitrogen, and oxygen. In a sample containing a mixture of only these three gases at exactly 1.00 atm, the partial pressure of carbon dioxide and nitrogen are 285 mmHg and 38.9 kPa, respectively. What is the partial pressure of oxygen? Gas Law ____________________________ o o. At 84 C, a gas in a container exerts a pressure of 0.503 atm. Assuming the size of the container has not changed, at what Celsius temperature would the pressure be 1.20 atm? Gas Law ____________________________ p. You have 11.2 L of an unknown elemental gas at 0.0 oC and 101.3 kPa. What is likely identity of this unknown gas if you find the mass to be approximately 2.0 grams? Gas Law ____________________________ q. Determine the pressure, in atm, exerted by oxygen gas at a temperature of 0°C. The density of oxygen gas is 1.43 g/L. r. In the reaction between hydrogen gas and oxygen gas, 6.50 L of water vapor was produced at STP. How many grams of hydrogen gas must have reacted with excess oxygen gas? s. Suppose a green plant produces 260.8 L of oxygen gas at 296 K and 98.0 kPa during cellular respiration. 1. What is the mass of glucose that is produced along with the oxygen? 2. What is the mass of water that is required to produce that much oxygen? a.

Water and Solutions Review Topics:    

Properties of Water and Liquids Factors influencing Rates of Dissolving, Solubility, and interpreting solubility curves Ions in Solution – Precipitation Reactions and Net Ionic Equations Concentrations of solutions – Molarity, molality, and dilution calculations

The exam will cover mostly material from moles, stoichiometry, and gas laws. Only a few questions will deal with the water and solutions unit since the quiz covered the material. Study Study Study!!!