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1 Name (PRINT clearly) Seat Number Exam 2 (100 points) Chemistry October 25, 2017 On my honor, I have neither given nor received unauthorized aid on this exam. Signed Date Write your answer in the blank. Only what is written CLEARLY in the blank will be graded! 1. (3 points) The molarity of a solution prepared by adding 80.0 grams of sodium hydroxide to enough water to make ml of solution is. 2. (3 points) A sample of a gas occupies 255 ml at 25 C and 760 mmhg. The volume of this gas at the same temperature and 950 mmhg is. 3. (5 points) The formation reaction of NaNO 3 (including states of all substances) is 4. (8 points) The complete ground state electron configuration for chromium, Cr, is. This atom contains unpaired electrons. The shorthand ground state configuration of the Cr 3+ ion is. 5. (3 points) From the atoms and ions in the previous problem, is(are) paramagnetic. 6. (8 points) For one electron in a 4f orbital, all the possible values of the quantum numbers are n =, l =, m l =, and m s = 7. (4 points) Which of the following pairs is(are) isoelectronic? [Please underline your answer(s)] Na + and K + Cl - and S 2- K + and Cl - Cr 3+ and Ar Cl - and Ar In the following problems, to receive any points, you must clearly and logically show how you arrive at your answer. All UNITS must appear at all steps of the calculation. NO WORK, NO UNITS, NO POINTS! 8. (6 points) A mixture of three gases has a total pressure of 1250 mmhg at 298 K. The mixture is analyzed and is found to contain 1.25 mol CO 2, 3.50 mol N 2, and 2.50 mole of O 2. What is the partial pressure of the N 2? 9. (7 points) A sample of N 2 O effuses from a container in 42 seconds. How long will it take the same amount of gaseous I 2 to effuse from the same container under the same conditions?

10. Consider the following net ionic equation. Page 2 a. (3 points) In this process is oxidized. 32 H + + 4 Cr2O 2-7 + 3 S 2-8 Cr 3+ + 3 SO 2-4 + 16 H 2 O b. (10 points) How many ml of a 0.

2 10. Consider the following net ionic equation. Page 2 a. (3 points) In this process is oxidized. 32 H Cr2O S 2-8 Cr SO H 2 O b. (10 points) How many ml of a M solution of K 2 S (molar mass, 110.2) will be required to react with grams of Fe 2 (Cr 2 O 7 ) 3 (molar mass, 759.6)? 11. (10 points) Chlorine gas reacts with fluorine gas to form chlorine trifluoride as shown below. Cl 2 (g) + 3 F 2 (g) 2 ClF 3 (g) Initially, Cl 2 and F 2 are separated as shown below. Assuming that when the valve is opened, the reaction goes to completion, determine what gases remain at the end and the partial pressure of each. Assume that the temperature remains constant at 25 C L atm 2.0 L 1.50 atm

3 Page (8 points) The energy required to completely remove an electron from sodium to form a sodium cation is 496 kj/mol. What is the minimum frequency of the light required to ionize sodium? SHOW ALL WORK, CLEARLY and LOGICALLY INCLUDING UNITS! 13. (12 points) If 10.0 grams of NaN 3 (molar mass, 65.0 g), the material used in automobile airbags, is detonated in a piston with an external pressure of atm and a temperature of 25 C, how much work is done? 2 NaN 3 (s) 2 Na (s) + 3 N 2 (g) 14. (10 points) To a sample of water at 25.6 C in a constant-pressure calorimeter of negligible heat capacity is added a 10.8 g piece of copper metal that has been heated to a temperature of C. If the final temperature of the water is 29.8 C, calculate the mass of the water in the calorimeter. (specific heat of copper is J/g. C).

4 Name (PRINT clearly) Seat Number Exam 2 (100 points) Chemistry October 25, 2017 On my honor, I have neither given nor received unauthorized aid on this exam. Signed Date Write your answer in the blank. Only what is written CLEARLY in the blank will be graded! 1. (3 points) The molarity of a solution prepared by adding 80.0 grams of sodium hydroxide to enough water to make ml of solution is. 2. (3 points) A sample of a gas occupies 255 ml at 25 C and 760 mmhg. The volume of this gas at the same temperature and 950 mmhg is. 3. (5 points) The formation reaction of NaNO 3 (including states of all substances) is 4. (8 points) The complete ground state electron configuration for chromium, Cr, is. This atom contains unpaired electrons. The shorthand ground state configuration of the Cr 3+ ion is. 5. (3 points) From the atoms and ions in the previous problem, is(are) paramagnetic. 6. (8 points) For an electron in a 4f orbital, the value of the quantum numbers are n =, l =, m l =, and m s = 7. (4 points) Which of the following pairs is(are) isoelectronic? [Please underline your answer(s)] Na + and K + Cl - and S 2- K + and Cl - Cr 3+ and Ar Cl - and Ar In the following problems, to receive any points, you must clearly and logically show how you arrive at your answer. All UNITS must appear at all steps of the calculation. NO WORK, NO UNITS, NO POINTS! 8. (6 points) A mixture of three gases has a total pressure of 1250 mmhg at 298 K. The mixture is analyzed and is found to contain 1.25 mol CO 2, 3.50 mol N 2, and 2.50 mole of O 2. What is the partial pressure of the N 2? 9. (7 points) A sample of N 2 O effuses from a container in 42 seconds. How long will it take the same amount of gaseous I 2 to effuse from the same container under the same conditions?

10. Consider the following net ionic equation. Page 2 a. (3 points) In this process is oxidized.

6534 M solution of K 2 S (molar mass, 110.2) will be required to react with 0.

(10 points) Chlorine gas reacts with fluorine gas to form chlorine trifluoride as shown below.

5 10. Consider the following net ionic equation. Page 2 a. (3 points) In this process is oxidized. 32 H Cr2O S 2-8 Cr SO H 2 O b. (10 points) How many ml of a M solution of K 2 S (molar mass, 110.2) will be required to react with grams of Fe 2 (Cr 2 O 7 ) 3 (molar mass, 759.6)? 11. (10 points) Chlorine gas reacts with fluorine gas to form chlorine trifluoride as shown below. Cl 2 (g) + 3 F 2 (g) 2 ClF 3 (g) Initially, Cl 2 and F 2 are separated as shown below. Assuming that when the valve is opened, the reaction goes to completion, determine what gases remain at the end and the partial pressure of each. Assume that the temperature remains constant at 25 C L atm atm

6 Page (8 points) The energy required to completely remove an electron from sodium to form a sodium cation is 496 kj/mol. What is the minimum frequency of the light required to ionize sodium? SHOW ALL WORK, CLEARLY and LOGICALLY INCLUDING UNITS! 13. (12 points) If 1.00 grams of NaN 3 (molar mass, 65.0 g), the material used in automobile airbags, is detonated in a piston with an external pressure of atm and a temperature of 25 C, how much work is done? 2 NaN 3 (s) 2 Na (s) + 3 N 2 (g) 14. (10 points) To a sample of water at 25.6 C in a constant-pressure calorimeter of negligible heat capacity is added a 10.8 g piece of copper metal that has been heated to a temperature of 100 C. If the final temperature of the water is 75.8 C, calculate the mass of the water in the calorimeter. (specific heat of copper is J/g. C).

Write your answer in the blank. Only what is written CLEARLY in the blank will be graded!

Write your answer in the blank. Only what is written CLEARLY in the blank will be graded! Name (PRINT clearly) Seat Number Exam 2 (100 points) Chemistry 1303.002 October 24, 2018 On my honor, I have neither given nor received unauthorized aid on this exam. Signed Date Write your answer in the