6. Calculate the solubility of Cu(N3)2 in water in grams per litre, where the Ksp = 6.3 x 10-10.

Equilibrium equation:

Cu(N3)2 (s) Cu2+ (aq) + 2 N3- (aq)

6.3 x 10-10 = (x)(2x)2 = 4x3

After solving for x we get x = 5.4 x 10-4 = [ Cu2+ ]. What is the maximum concentration of Cu(N3)2 that can dissolve in aqueous solution?

a) [ Cu(N3)2 ] = [ Cu2+ ]2
b) [ Cu(N3)2 ] = [ Cu2+ ]
c) [ Cu(N3)2 ] = 2 [ Cu2+ ]
d) [ Cu(N3)2 ] = [ Cu2+ ][ N3- ]2