Notifications
Clear all
Equilibrium
1
Posts
2
Users
0
Likes
206
Views
0
24/10/2021 10:12 am
Topic starter
On addition of increasing amount of AgNO3 to 0.1 M each of NaCl and NaBr in a solution, what % of Br- ion get precipitated when Cl- ion starts precipitating. Ksp (AgCl) = 1.0 x 10-10, Ksp (AgBr) = 1 x 10-13
(a) 0.11
(b) 99.9
(c) 0.01
(d) 9.99
1 Answer
0
24/10/2021 10:19 am
Correct answer: (b) 99.9
Explanation:
To precipitate the AgCl
[Ag+] required
= \(\frac{K_{sp}(AgCl)}{[Cl^-]}\) = \(\frac{1.0 \times 10^{-10}}{0.1}\)
= 1.0 x 10-9 M
[Br-] left at this stage = \(\frac{K_{sp}(AgBr)}{[Ag^+]}\)
= \(\frac{1.0 \times 10^{-13}}{1.0 \times 10^{-9}}\) = 1.0 x 10-4 M
% of remaining
[Br-] = \(\frac{1.0 \times 10^{-4}}{0.1} \times 100\) = 0.1
% of Br- to be precipitated
= 100 - 0.1 = 99.9