Question

1. * Put in order from lowest to highest boiling point

0.17 m Ba(NO3)2

0.14 m Fe(CH3COO)2

0.15 m CrCl2

0.49 m Sucrose( nonelectrolyte)

2. A student measures the S2- concentration in a saturated aqueous solution of silver sulfide to be 2.99 x 10^-17 M

The solubility product constant for silver sulfide is _____

Answer 1

1) answer : 0.17 m Ba(NO3)2

explanation:

0.17 m Ba(NO3)2 -----------------> i = 3 , BP = 0.17 x 3 = 0.51

0.14 m Fe(CH3COO)2----------> i= 3 , BP = 0.14 x 3 = 0.42

0.15 m CrCl2 ------------------> i=3 , BP = 0.15 x 3 = 0.45

0.49 m Sucrose( nonelectrolyte)-------> i =1 , BP = 0.49

order of BP   : 0.17 m Ba(NO3)2 >0.15 m CrCl2>0.14 m Fe(CH3COO)2 >0.49 m Sucrose( nonelectrolyte)

2)

Ag2S --------------------------------> 2Ag+                   + S^-2

                                                   1.495x10^-17M          2.99 x 10^-17 M

Ksp = [Ag+]^2 [S^-2]

Ksp = (1.495x10^-17)^2 (2.99 x 10^-17)

Ksp = 6.68 x 10^-51