Arkansas State University Department of Chemistry and Physics

1. Write the equilibrium expression for each of the following:  Where possible, express both K_c and K_p.
 

a)	2 NaN3 (s)		2 Na (s)   +    3 N2 (g)
b)	4 NH3 (g)  +  5 O2 (g)		4 NO (g)  +   6 H2O (g)
c)	2 HCl (aq)  + Ca(OH)2 (aq)		2 H2O (l)  +  CaCl2 (aq)

2. For equation 1b, would K_c = K_p?  Explain.

3. Determine the equilibrium concentrations for each species in the equation:
 

H2 (g)   +    I2 (g)

2 HI (g)

 if the initial concentrations of H₂ and I₂ are 1.0 M and K_c = 54.3 at 430^oC.

4. Given the reaction below:
 

H2 (g)   +    I2 (g)

2 HI (g)

If the initial concentrations of H₂ and I₂ are 1.0 M and the initial concentration of HI is 0.5 M (Kc = 54. 3 at 430^oC), is the reaction at equilibrium?  If not, which way will the reaction proceed?

5. According to Le Chatelier's Principle,

a) what effect would the addition of Cl ^- have on the equilibrium below?
 

CoCl2   +   2 Cl -

CoCl42-

b) what effect would the addition of Ag⁺ have on the equilibrium in problem 5a if the Ag⁺ precipitates as AgCl?
 

answers