4. Which of the following gas molecules will have the highest average velocity at 500K? a. H 2 b. He c. CH 4 d. C 2H 6

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1 Multiple hoice (3 pts each) 1. In which of the following processes will work be positive? Assume the pressure remains constant for all examples. a. 2(l) 2(g) at constant temperature b (l) (g) 16 2(g) (l) at constant temperature c. 2(g) 2(s) at constant temperature d. 2(g) at 150 2(g) at Which of the following chemical reactions are redox reactions. a. 2(g) + 1 / 2 2(g) 2(g) b. 2(g) + 1 / 2 2(g) 2(l) c. N 3(aq) + Na(aq) 2(l) + NaN 3(aq) d. AgN 3(aq) + Nal(aq) Agl(s) + NaN 3(aq) 3. What is the oxidation number of the nitrogen atom in nitrate? a. +1 b. +3 c. +5 d Which of the following gas molecules will have the highest average velocity at 500K? a. 2 b. e c. 4 d According to the reaction given below, what is D f for gaseous hydrochloric acid? a kj b kj c kj d kj 2 l(g) 2(g) + l 2(g) D = kj 6. ow many acidic hydrogens are in the following molecule? a. 1 b. 2 c. 3 d What is the concentration of hydroxide ions in a 0.100M a() 2 solution? a M b M c M d M 8. Which of the following changes would lead to more ideal behavior of a gas? a. Increase the volume of the container b. Decrease the temperature c. Increase the pressure inside the container d. Decreasing the volume of the container

2 9. A water sample has a change in temperature of What is the temperature change of the water sample in Kelvin? a K b K c K d K 10. Which of the following gases would behave most like an ideal gas? a. 4 b. 2 6 c. 3 8 d True/False (2 pts each) 1. The following process is exothermic. 2(l) 2(g) 2. The following process has an increase in entropy. 2(l) 2(g) 3. Energy is released when a bond is broken. 4. The following reaction is exothermic. N 3(g) N(g) + 3(g) 5. The molar volume of an ideal gas with a pressure and temperature of 1.00 atm and 25.0 respectively is 22.4 L. 6. If a system is defined as a sample of liquid water, then D for the system is negative when the water evaporates. 7. Below is the correctly balanced net ionic equation for the oxidation of copper using aqueous silver. Ag + (aq) + u(s) Ag(s) + u 2+ (aq) 8. The velocity of each oxygen molecule at 3.00x10 2 Kelvin is 483 m/s. 9. Based on the activity series of metals, the following reaction would occur. o(s) + al 2(aq) ol 2(aq) + a(s)

3 10. The change in energy for the reaction represented by the following diagram can be calculated by the addition of arrow 1 and arrow 2. Reactants 1 Energy 2 Products Reaction Progress Short Answer - Must show all work to receive credit, please box answers 1. alculate the work (in Joules) for the following process? (3) Initial conditions P = 1.00 atm V = L Final conditions P = 1.00 atm V = L 2. An ideal gas is placed into a sealed container with a fixed volume. The initial temperature and pressure of the container are 29.6 and atm respectively. The container and gas are heated to What is the resulting pressure? (3)

4 3. Below are two chemical reactions along with two energy diagrams. The first reaction shows the combustion of methane ( 4) in the liquid form. The second shows the combustion of methane in the gaseous form. Assign each reaction to the proper energy diagram by writing the reaction number below the appropriate diagram. (2) 1. 4(l) + 2 2(g) 2(g) + 2 2(l) 2. 4(g) + 2 2(g) 2(g) + 2 2(l) Reactants Energy Energy Reactants Reaction Progress Products Reaction Reaction Progress Products Reaction 4. Using the three reactions below, determine the D for the combustion of ethane ( 2 4). (3) 2 4(g) + 3 2(g) 2 2(g) + 2 2(g) 2(graphite) + 2 2(g) 2 4(g) D 1 = kj 2(g) + 1 / 2 2(g) 2(g) D 2 = kj (graphite) + 2(g) 2(g) D 3 = kj

5 5. Shown below is the combustion reaction for propane ( 3 8). alculate the change in enthalpy per mole of propane using only bond energies. (4) A student conducted an experiment to determine the specific heat of a metal sample. She used a coffee cup calorimeter similar to what was used in lab. She placed grams of metal originally at into the calorimeter containing grams of water initially at The final temperature of the water and metal was determined to be alculate the specific heat of the metal? (4)

6 7. A student was asked to determine the concentration of an iron (III) chloride solution by titrating with tin (II) chloride according to the reaction shown below. (7) 2Fel 3(aq) + Snl 2(aq) 2Fel 2(aq) + Snl 4(aq) a. A ml sample of the Fel 3 solution required ml of M Snl 2(aq) to completely reduce Fe 3+ to Fe 2+. alculate the concentration of Fel 3 in the solution provided to the student. (4) b. What is the oxidation number of tin in Snl 4? (1) c. What is the reducing agent? (1) d. What is the oxidizing agent? (1) 8. Below is the Lewis dot structure for an organic acid. Write out the chemical equation for the neutralization reaction between this acid and sodium hydroxide. (3)

7 9. A series of experiments were conducted to determine the Lewis dot structure of an unknown material. (6) a. First, grams of the material was placed into an evacuated 0.500L container. The temperature was raised to K, and the resulting pressure was 1.00 atm. alculate the molar mass of the unknown material? (4) b. Next, the molecule was subjected to a series of structural tests to determine bond energies. Some of the bonds within the molecule were determined to have a bond energy of 467 kj/mol. Which of the molecules below is the most likely structure of the unknown material? ircle your answer. (2)

8 10. Answer the following questions regarding the following reaction for the combustion of propane ( 3 8). (7) 3 8(g) + 5 2(g) 3 2(g) + 4 2(g) a. Using enthalpies of formation provided on the exam, determine D (kj/mol) for the reaction. (3) b. ow much heat can be generated when grams of propane are allowed to react with grams of oxygen? (4) 11. Determine the oxidation number for each atom indicated with an arrow. Write the oxidation number in the appropriate box. (3) l N

9 12. alculate the kinetic energy (in Joules) of an individual molecule of nitrogen travelling with a velocity of m/s. (3) 13. In lecture I performed a demonstration where I placed electrodes into a solution of Snl 2 producing tin solid. The portion of the reaction responsible for the formation of solid tin is shown below. (4) Sn 2+ (aq) + 2e - Sn(s) a. Is this the oxidation or reduction half reaction? (1) b. n a previous occasion I performed this reaction and collected the solid tin produced. The reaction produced grams of tin. ow many electrons were used to produce this much solid? (3) 14. Write the two resonance structures for acetate ( ). (4)

10 15. Answer the following questions about the following reaction. (6) a. Write the net ionic equation. (3) Nal(aq) + 2l(aq) l 2(g) + 2(l) + Nal(aq) b. What is the oxidation number of the chlorine atom in Nal? (1) c. What is the oxidation number of the chlorine atom in l? (1) d. What is the oxidation number of the chlorine atoms in l 2? (1)

Name: Thermochemistry. Practice Test C. General Chemistry Honors Chemistry

Name: Thermochemistry. Practice Test C. General Chemistry Honors Chemistry Name: Thermochemistry C Practice Test C General Chemistry Honors Chemistry 1 Objective 1: Use the relationship between mass, specific heat, and temperature change to calculate the heat flow during a chemical