Download App

6.2. Equilibrium - II (icon Equilibrium) — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistry6.2. Equilibrium - II (icon Equilibrium)1 Mark
MCQ
A buffer solution with $pH$$=9$ is to be prepared by mixing $N{H_4}Cl$ and $N{H_4}OH$. Calculate the number of moles of $N{H_4}Cl$ that should be added to one litre of $1.0\,M\;N{H_4}OH.\,$ $[{K_b} = 1.8 \times {10^{ - 5}}]$
  • A
    $3.4$
  • B
    $2.6$
  • C
    $1.5$
  • ✓
    $1.8$
✓

Answer

Correct option: D.
$1.8$
(d) $pH = - {\rm{log}}\,\,{K_b} + {\rm{log}}\frac{{{\rm{[Salt]}}}}{{{\rm{[Acid]}}}}$

$pH = - {\rm{log}}\,[1.8 \times {10^{ - 5}}] + {\rm{log}}\frac{{{\rm{[Salt]}}}}{{{\rm{1}}{\rm{.0}}}}$

$9 = 4.7 + \log \frac{{{\rm{[Salt]}}}}{{1.0}}$ ; $\log \frac{{{\rm{[Salt]}}}}{{1.0}} = 4.7 - 9 = - 4.3$

$\frac{{{\rm{[Salt]}}}}{{1.0}} = {\rm{Antilog}}\frac{1}{{4.3}};\,\,[S{\rm{alt]}} = 1.8$

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

More "M.C.Q (1 Marks)" from 6.2. Equilibrium - II (icon Equilibrium)→6.2. Equilibrium - II (icon Equilibrium) — all question types→Chemistry STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Which of the following undergoes chlorination at fastest rate ?
→
Which one is oxidising agent in the reaction below

$2CrO_4^{2 - } + 2{H^ + } \to C{r_2}O_7^{2 - } + {H_2}O$

→
The order of increasing ionic radius of the following is
→
Among the alkali metals, the metal with the highest ionisation potential is:
→
If $W$ is mass number and $N$ is the atomic number of an element, then
→
Consider the reactions given below. On the basis of these reactions find out which of the algebric relations given in options $(i)$ to $(iv)$ is correct?
  1. $\text{C}(\text{g})+4\text{H}(\text{g})\rightarrow\text{CH}_4(\text{g});\Delta_\text{r}\text{H}=\text{x}\text{kJ}\ \text{mol}^{-1}$
  2. $\text{C}(\text{graphite,s})+2\text{H}_2(\text{g})\rightarrow\text{CH}_4(\text{g});\Delta_\text{r}\text{H}=\text{y}\text{kJ}\ \text{mol}^{-1}$​​​​
→
Match List $I$ with List $II$.

List $I$ (Compound) List $II$ (Shape/geometry)
$A$. $\mathrm{NH}_3$ $I$. Trigonal Pyramidal
$B$. $\mathrm{BrF}_5$ $II$. Square Planar
$C$. $\mathrm{XeF}_4$ $III$. Octahedral
$D$. $\mathrm{SF}_6$ $IV$. Square Pyramidal

Choose the correct answer from the options given below:

→
The ionization energies from $\ce{Ga}$ to $\ce{Tl}$ do not decrease due to :
→
Arrange the following in order of increasing dipole moment : $H_2O,\,H_2S,\, BF_3$.
→
An electronic transition from $1s$  orbital of an atom causes
→