When 1.88 ~g of AgBr(s) is added to a 10^-3 M aqueous solution of KBr , the concentration of Ag^+ is 5 × 10^-10 M . if the same amount of AgBr(s) is added to a 10^-2 M aqueous solution of AgNO 3 , the concentration of Br is:

Correct answer: (D) 5 × 10^-11 M. K_SP AgBr= (Ag^+ )(Br)= (5 × 10^-10 ) (10^-3 )=5 × 10^-13 Concentration of Br in 10^-2 M aq AgNO_3=fracKsp AgBr [Ag^+ ] =frac5 × 10^-13 (10^-2 )=5 × 10^-11 ~m

Q6 / 90 · KVPY 2014 (SB/SX) · Chemistry

When $1.88 \mathrm{~g}$ of $\mathrm{AgBr}(\mathrm{s})$ is added to a $10^{-3} \mathrm{M}$ aqueous solution of $\mathrm{KBr}$, the concentration of $\mathrm{Ag}^{+}$is $5 \times 10^{-10} \mathrm{M}$. if the same amount of $\mathrm{AgBr}(\mathrm{s})$ is added to a $10^{-2} \mathrm{M}$ aqueous solution of $\mathrm{AgNO} 3$, the concentration of $\mathrm{Br}$ is:

A
$9.4 \times 10^{-9} \mathrm{M}$
B
$5 \times 10^{-10} \mathrm{M}$
C
$1 \times 10^{-11} \mathrm{M}$
Correct answer
D
$5 \times 10^{-11} \mathrm{M}$

Solution

$\mathrm{K}_{\mathrm{SP}} \mathrm{AgBr}=\left(\mathrm{Ag}^{+}\right)(\mathrm{Br})=\left(5 \times 10^{-10}\right)\left(10^{-3}\right)=5 \times 10^{-13}$ Concentration of $\mathrm{Br}$ in $10^{-2} \mathrm{M}$ aq $\mathrm{AgNO}_{3}=\frac{\mathrm{Ksp} \mathrm{AgBr}}{\left[\mathrm{Ag}^{+}\right]}$ $$ =\frac{5 \times 10^{-13}}{\left(10^{-2}\right)}=5 \times 10^{-11} \mathrm{~m} $$

Hence, the correct answer is option: 'D'.

Solution

More Solid State Questions