1.  What mass of SiCl4(g) is required to fill a volume of 15.5 L at STP?

 

2.  A sample of ammonia (NH3) gas is completely decomposed to nitrogen and hydrogen gases by heating over iron wool.  If the total pressure is 866 mm Hg, what are the partial pressures of N2 and H2?  (Write the reaction)

 

3.  A 2.00 L sample of O2 (g) had a pressure of 785 torr and 25 °C.  If the pressure is reduced to .450 atm at 45 °C, what is the final volume?

 

4.  What volume of ammonia at 1.3 atm and 35 °C is needed to produce 45 g of urea?

            2 NH3 (g)  +  CO2 (g)  ®  H2NCONH2 (s)  +  H2O (g)

5.  Calculate the ΔHºrxn for:

 

4 NO(g)  +  6 H2O(g)   →   4 NH3(g)  +  5 O2(g)   

Given:             ΔHºf    (kJ/mole)

NH3(g)            –46

O2(g)               0

NO(g)              90.

H2O(g)            – 242

 

6.  Calculate the enthalpy of reaction for:

C6H4O2 (aq)  + 2 H2O(l)   ®   C6H4(OH)2 (aq)  +  H2O2 (aq)

Given:                                                                         DH°

C6H4(OH)2 (aq) ® C6H4O2 (aq)  +  H2 (g)                + 177.4 kJ

H2 (g)  + O2 (g) ® H2O2 (aq)                                     -  191.2 kJ

H2 (g)  + ½ O2 (g) ® H2O (g)                                    -  214.8 kJ

H2O (g) ® H2O(l)                                                      -  43.8 kJ

____________________

 

 

7.  If 15 grams of ice at 0.0 ºC is added to 75 grams of water at 25 ºC, what is the final temperature of the mixture?  s (water) = 4.184 J/gºC.  ΔHfusion ice = 333J/g.

 

 

8.  The bond energy of N2 is 941 kJ/mole.  What is the wavelength ( in nm) of photons needed to break the nitrogen bond?

 

9.  Which has more molecules:          5.0 g of H2       or         60.L of SF6 at STP?

 

 

10.  Calculate the Molar Mass of a compound that has a mass of 1.25 g and occupies a volume of 126 mL at a pressure of 756 Torr at 98 °C.