6well i m not gettin rite answers by these methods
1st one is not as simple as it looks!!!
second one too the ans is not rite....
1. How much ammonia must be added to a 0.004 M Ag+ soln. to prevent the precip. of AgCl when [Cl-] reaches 0.001 M ? Ksp (AgCl) = 1.8 * 10 ^ -10 . Diss. const. for Ag(NH3)2 + = 6 * 10 ^ -8.
2. A conc. strong acid is added to a solid mixture of 0.015 mole samples of Fe (OH)2 and Ca (OH)2 placed in 1 L of water . At what value of pH will the dissolution of each hydroxide be complete? (Assume negligible volume change)
Ksp[Fe(OH)2 = 7.9 * 10 ^ -15 and Ksp [Ca (OH)2 = 1.6 * 10^-19
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7 Answers
1357[Ag+][Cl-]=1.8*10-10
So [Ag+]=1.8*10-7
Ag(NH3)2+=0.004 M
Find [NH3]
1357Let the conc of Fe2+=x and OH-=y
then concentration of Ca2+=0.015-x
xy2=Ksp1
(0.015-x)y2=Ksp2
solve for x and y
61357my answer for first one
[NH3]2=6×10-8*4*10-4/1.8*10-7=4/3 * 10-4
[NH3]=0.01155 M