Ch. 13 gas                    test      [60 points]

For problems involving calculations, show your work in an organized manner, include any relevant equation (or formula and conversion factor(s)), put the proper units in your calculations / answer, and have the proper number of significant figures in your answer.

Academic Honesty:   The answers on this test are my own and I am using only the allowed set of notes as described in the syllabus.  I have not discussed the test questions with anyone before or during the test nor have I seen the test questions prior to the exam.  If you violate any of the preceding items or do not sign, your semester grade is a F.

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1.  N2 gas is stored in a 5.0 L container at 25 °C and has a pressure of 4.0 atm, while a 7.0 L container with H2 gas is at 37 °C and has a pressure of 12.0 atm.  There is a valve connecting both gas containers; opening this valve allows the gases to react to form ammonia, NH3.  Assume that the temperature in the container is 37 °C and that the valve’s volume is zero.  [30 points]

a.  Determine the number of moles of ammonia formed in the reaction.

b.  Determine the partial pressure of ammonia in the container ?

2.  The below manometer is filled with mercury, where h = 35 mm Hg and the atmospheric pressure is 95 kPa.  What is the pressure in the system (in atm) ?  [10 points]

3. Gas law problems.  [20 points]

a. A 24 mL syringe has a pressure of 95 kPa.  The syringe is sealed, then its volume was decreased to 15 mL; what is the new pressure in the syringe ?

b. A 24 mL syringe has a pressure of 95 kPa at 21 °C.  The syringe is sealed, then its volume was decreased to 15 mL and put into a refrigerator at 4.0 °C; what is the new pressure in the syringe ?