MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Salt of Weak Acid and Strong Base

Which of the ...

Question

Which of the following concentrations of $N H_{4}^{+}$ will be sufficient to prevent the precipitation of $M g (O H)_{2}$ from a solution which is $0.01 {M MgCl}_{2}$ and $0.1 {M NH}_{3} (a q)$ ? Given that the $K_{s p}$ of $M g (O H)_{2} = 2.5 \times 10^{- 11}$ and $K_{b}$ for $N H_{3} (a q) = 2 \times 10^{- 5}$ .

A

0.01 M

No worries! We‘ve got your back. Try BYJU‘S free classes today!

B

0.02 M

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

0.03 M

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

0.04 M

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D 0.04 M
$K_{s p} M g (O H)_{2} = [M g^{2 +}] [O H^{-}]^{2} = 2.5 \times 10^{- 11}$
$∴ [O H^{-}] = \sqrt{\frac{2.5 \times 10^{- 11}}{0.01}} = 5 \times 10^{- 5}$
now $K_{b} N H_{3} = 2 \times 10^{- 5} = \frac{[N H_{4}^{+}] [O H^{-}]}{[N H_{3}]}$
hence
$[N H_{4}^{+}] = 0.04 M$

Suggest Corrections

thumbs-up

0

Similar questions

Q. Which of the following concentrations of

N H_{4}^{+}

will be sufficient to prevent the precipitation of

M g (O H)_{2}

from solution is 0.01 M

M g C l_{2}

0.1 M N H_{3} (a q)

K_{s p}

M g (O H)_{2} = 2.5 \times 10^{- 11}

K_{b}

N H_{2} (a q) = 2 \times 10^{- 5}

Q. Which of the following concentrations of

N H_{4}^{+}

will be sufficient to prevent the precipitation of

M g (O H)_{2}

from a solution which is

0.01 {M MgCl}_{2}

0.1 {M NH}_{3} (a q)

? Given that the

K_{s p}

M g (O H)_{2} = 2.5 \times 10^{- 11}

K_{b}

N H_{3} (a q) = 2 \times 10^{- 5}

.

Q. Which of the following concentrations of

N H_{4}^{+}

will be sufficient to prevent the precipitation of

M g (O H)_{2}

form a solution which is 0.01 M

M g C l_{2}

N H_{3}

K_{S P}

M g (O H)_{2} = 2.5 \times 10^{- 11}

K_{b}

N H_{3} (a q) = 2 \times 10^{- 5}

Q. What is the maximum pH of a solution

0.10 M

{M g}^{2 +}

M g {(O H)}_{2}

will nor precipitate? Given,

K_{s p} [M g {(O H)}_{2}] = 1.2 \times 10^{- 11}

Q. Find moles of

N H_{4} C l

required to prevent

M g (O H)_{2}

from precipitating in a litre of solution which contains 0.02 mole of

N H_{3}

and 0.001 mole of

M g^{2 +}

K_{b} (N H_{3}) = 10^{- 5}; K_{s p} [M g (O H)_{2}] = 10^{- 11}

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Hydrolysis

CHEMISTRY

Watch in App

explore_more_icon

Explore more

Salt of Weak Acid and Strong Base

Standard XII Chemistry

Join BYJU'S Learning Program

CrossIcon