What is the molar solubility of Mn(OH)_2 (K_ sp = 4.5 10^ -14 ) in a buffer solution contain equal moles of NH_4^+ and NH_3 (K_b = 1.8 10^ -5 ) ?

What is the molar solubility of Mn(OH)_2 (K_ sp = 4.5 10^ -14 ) i…

MCQ

What is the molar solubility of $Mn(OH)_2$ $(K_{sp} = 4.5\times10^{-14})$ in a buffer solution contain equal moles of $NH_4^+$ and $NH_3$ $(K_b = 1.8\times10^{-5})$ ?

A
$3.0\times10^{-4}$
✓
$1.38\times10^{-4}$
C
$1.3\times10^{-3}$
D
$7.3\times10^{-4}$

✓

Answer

Correct option: B.

$1.38\times10^{-4}$

b
Basic buffer $\mathrm{pOH}=\mathrm{pkb}+\log \frac{\left[\mathrm{NH}_{4}^{+}\right]}{\left[\mathrm{NH}_{3}\right]}$

$=4.74$

$\left[\mathrm{OH}^{-}\right]=1.80 \times 10^{-5}$

$\mathrm{K}_{\mathrm{sp}}, \mathrm{Mn}(\mathrm{OH})_{2}=\mathrm{S} \times[\mathrm{OH}]^{2}$

$\therefore S=\frac{k_{s p}}{\left[O H^{-}\right]^{2}}=\frac{4.5 \times 10^{-14}}{1.8^{2} \times 10^{-10}}$

$S=1.38 \times 10^{-4}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

JEE STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Match each of the diatomic molecules in Column $I$ with its property $/$ properties in Column $II$.

Column $I$	Column $II$
$(A)$ $\mathrm{B}_2$	$(p)$ Paramagnetic
$(B)$ $\mathrm{N}_2$	$(q)$ Undergoes oxidation
$(C)$ $\mathrm{O}_2^{-}$	$(r)$ Undergoes reduction
$(D)$ $\mathrm{O}_2$	$(s)$ Bond order $\geq 2$
	$(t)$ Mixing of $'\mathrm{s}\ '$ and $'\mathrm{p}\ '$ orbitals