Ch. 13 & 15  gas & solution  test      65 points                                             chem

 

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.

 

                                                                                                Signature:  ___________________

 

1.  Determine the final pressure based on the following information.  [10 points]

 

Condition

Volume (mL)

Pressure (kPa)

Temperature (°C)

initial

45.0

95.0

21.0

final

25.0

?

4.0

 

2.  A container has 14.0 g nitrogen gas, 24.0 g oxygen gas, and 6.0 g hydrogen gas in a 2.5 L container at 35.0 °C  ?  [10 points]

a.  what is the mole fraction of nitrogen ?

 

 

b.  what is the partial pressure of nitrogen gas ?

 

 

3.   At STP,     N2 (g)  +  H2 (g)  à  NH3 (g)        [20 points]

                      5.0 L     12.0 L        

 

a.  balance the above chemical equation

 

b.  determine the number of moles of each gas before the reaction

 

c.  identify the limiting reactant; justify your choice.

 

d.  determine the number of grams of NH3 at the end of the reaction ?

 

4.  Describe how to prepare 275 mL of a 525 mM aqueous solution of glucose, C6H12O6  ?   [hint:  use solid glucose and water; 10 points]

 

5.  10.0 mL of 25 mM silver nitrate aqueous solution was mixed with 15.0 mL of a 20.0 mM potassium chloride aqueous solution.  [hint:  see outline in question 3; 15 points]