Chemistry MCQs for NEET — Practice Questions with Answers

${\mathrm{CH}}_3\mathrm{COOH} + \mathrm{NaOH} \stackrel{ }{\to }{\mathrm{CH}}_3\mathrm{COONa} + {\mathrm{H}}_2\mathrm{O}$

At t=0    60ml 1M   20ml 1M         0          0

At t='t'   40ml 1M        0         20ml 1M     -

Now it is the acidic buffer solution.

$$\begin{gathered} \mathrm{pH}=-\mathrm{logKa} + \log \frac{\left[\mathrm{salt}\right]}{\left[\mathrm{acid}\right]} \\ \mathrm{pH}=-\log 1.8 \times {10}^{-5}\log \frac{20\times 1}{40\times 1} \\ \mathrm{pH}=4.75 - 0.3 \\ \mathrm{pH}=4.45 \end{gathered}$$

In NH₄OH, Ag⁺ form complex. Hence, Solubility of AgCl is maximum in NH₄OH.

Use, ${\mathrm{K}}_{\mathrm{p}}={\mathrm{K}}_{\mathrm{c}}(\mathrm{RT}{)}^{∆{\mathrm{n}}_{\mathrm{s}}}$

Use, 

$\mathrm{\alpha }=\frac{\mathrm{D}-\mathrm{d}}{(\mathrm{n}-1)\mathrm{d}}$

D=Theorotical vapour dessity

d= Observed apour density

n= No. of moles obtained after dissociation after one mole

$\mathrm{\alpha }=\frac{46-41}{(2-1)41}=0.122$

% dissociation = 12.2%

On adding inert gas at constant pressure, equilibrium shifts in tht direction where the number of moles are more.

$$\begin{gathered} \mathrm{Mg}(\mathrm{OH}{)}_2\rightleftharpoons {\mathrm{Mg}}^{2+} + 2{\mathrm{OH}}^{-} \\ {\mathrm{K}}_{\mathrm{sp}}=[{\mathrm{Mg}}^{2+}] [{\mathrm{OH}}^{-}{]}^2 \\ 9 \times {10}^{-12}=0.01 \times \left[{\mathrm{OH}}^{-}{]}^2 \\ \right[{\mathrm{OH}}^{-}] =3 \times {10}^{-5}\mathrm{M} \end{gathered}$$

${\mathrm{CH}}_3\mathrm{COOH} + \mathrm{NaOH} \to {\mathrm{CH}}_3\mathrm{COONa} + {\mathrm{H}}_2\mathrm{O}$

At t=0          1        0.5          0        0

Att t='t'       0.5        0         0.5      0.5

Now it is the acidic buffer solution.

All weak acid has strong conjugate base and strong acid has weak conjugate base.

On heating dissociationof H₂O increases. SO, [H⁺] as well s [OH^-] increases and pH as well as pOH decreases.

When pressure of CO₂ gas greater than K_p then it can't shift in backward direction without CaO.