MCQ
A buffer solution contains $1\ mole$ of ammonium sulphate and $1\ mole$ of $NH_4OH$ ($K_b = 10^{-5}$). The $pH$ of solution will be
- A$5$
- B$9$
- C$5.3$
- ✓$8.7$
✓
Answer
Correct option: D.
$8.7$
d
$\mathrm{pOH}=\mathrm{pK}_{\mathrm{b}}+\log \frac{[\mathrm{Salt}]}{[\mathrm{Base}]}=\mathrm{pK}_{\mathrm{b}}+\log \frac{[\mathrm{Cation}]}{[\mathrm{Base}]}$
$\mathrm{pOH}=\mathrm{pK}_{\mathrm{b}}+\log \frac{[\mathrm{Salt}]}{[\mathrm{Base}]}=\mathrm{pK}_{\mathrm{b}}+\log \frac{[\mathrm{Cation}]}{[\mathrm{Base}]}$
$\left[\mathrm{NH}_{4}^{+}\right]=2 \times$ mole of $\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4}$
$\therefore \mathrm{pOH}=5+\log 2=5.3$
or $\mathrm{pH}=8.7$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Slaked lime on treatment with chlorine produces a compound $(X)$. What is the oxidation state of chlorine in the $'X' $?
→The $pH$ indicators are
→Number of two electron can have the same values of …… quantum numbers
The hybridization of the central atom in $ICl^+_2$ is
→Three moles of an ideal gas are compressed isothermally from $60 \mathrm{~L}$ to $20 \mathrm{~L}$ using constant pressure of $5 \mathrm{~atm}$. Heat exchange $Q$ for the compression is - . . . . . . . . . .Lit. atm.
→Water decomposes at $2300\,K$
→$H _2 O ( g ) \rightarrow H _2( g )+\frac{1}{2} O _2( g )$
The percent of water decomposing at $2300\,K$ and $1\,bar$ is $...........$ (Nearest integer).
Equilibrium constant for the reaction is $2 \times 10^{-3}$ at $2300\,K$
Which of the following $\sigma$ -bonds participate in hyperconjugation ?
→he common refrigerant chlorofluoromethane $($Freon$)$ and $\text{NOx}$ is a serious pollutant because?
→In a chemical reaction $A + 2B \overset K \rightleftharpoons 2C + D$, the initial concentration of $B$ was $1.5$ times of $A$ but the equilibrium concentrations of $A$ and $B$ were found to be equal. The equilibrium, constant $(K)$ for the aforesaid chemical reaction is
→$1-$butyne reacts with cold alkaline $KMn{O_4}$ to produce
→