(1)设AgCl在水中的溶解度为S1(mol/L), Ag2CrO4的溶解度为S2(mol/L)
则 AgCl ==== Ag+ + Cl-
S1 S1 S1
Ksp(AgCl)=c(Ag+)*c(Cl-)= S1^2 = 1.8 * 10^(-10)
解得S1=1.342 * 10^(-5) mol/L
Ag2CrO4 ==== 2Ag+ + CrO4-
S2 2 * S2 S2
Ksp(Ag2CrO4)= c(Ag+) ^2 * c(CrO4-) =( 2 * S2)^2 * S2
=2.0 *10^(-12)
解得 S2 = 7.937 * 10^(-5) mol/L
(2)设AgCl在0.10 mol/L AgNO3 溶液中的溶解度为S3(mol/L), Ag2CrO4的溶解度为S4(mol/L)
AgCl ==== Ag+ + Cl-
S3 S3 +0.1 S3
由于同离子效应,S3《0.1,故S3+0.1≈0.1
Ksp(AgCl)=c(Ag+)*c(Cl-)= 0.1 * S3 =1.8 *10^(-10)
解得 S3 = 1.8 * 10^(-9) mol/L
Ag2CrO4 ==== 2Ag+ + CrO4-
S4 2 * S4 + 0.1 S4
由于同离子效应 2*S4《 0.1 ,所以 2 * S4 + 0.1 ≈0.1
Ksp(Ag2CrO4)= c(Ag+) ^2 * c(CrO4-) = 0.1^2 * S4 =2.0*10^(-12)
解得 S4 = 2 * 10^(-10) mol/L