Equilibrium practice · Mixed difficulty

Which of these is a Lewis acid?

The equilibrium constants for the reaction $\mathrm{A}_2 \rightleftharpoons2 \mathrm{A}$ at $500 \mathrm{~K}$ and $1000 \mathrm{~K}$ are $1 \times 10^{-10}$ and $1 \times 10^{-5},$ respectively. The reaction is

Number of ${\mathrm{H}^ + }$ ions present in $10\;mL$ of a solution of $pH\; = \;3$ is:

The percentage error in $\mathrm{H}^{+}$concentration provided by $10^{-8} \mathrm{~M} \mathrm{~HCl}$ if ionisation of water is not neglected is :

Among $\mathrm{BM}{\mathrm{e}_3},\mathrm{B}{\mathrm{F}_3},\mathrm{BC}{\mathrm{l}_3}\;\mathrm{and}\;{\mathrm{B}_2}{\mathrm{H}_6}$ which one will be the best Lewis acid?

A weak acid $\mathrm{H}X\left( {{K_a} = 1 \times {{10}^{ - 5}}} \right)$ on reaction with $\mathrm{NaOH}$ gives $\mathrm{Na}X$. For $0.1\;M$ aqueous solution of $\mathrm{Na}X$, the $\%$ hydrolysis is:

Solid $\mathrm{BaF}_2$ is added to a solution containing 0.1 mole of $\mathrm{Na}_2 \mathrm{C}_2 \mathrm{O}_4$ solution $(1 \mathrm{~L})$ until equilibrium is reached. If the $K_{\mathrm{sp}}$ of $\mathrm{BaF}_2$ and $\mathrm{BaC}_2 \mathrm{O}_4$ is $10^{-6}$ $\mathrm{mol}^3 \mathrm{~L}^{-3}$ and $10^{-10} \mathrm{~mol}^2 \mathrm{~L}^{-2},$ respectively, then find the equilibrium concentration of $\mathrm{Ba}^{2+}$ in the solution. Assume that addition of $\mathrm{BaF}_2$ does not cause any change in volume.

3.2 moles of hydrogen iodide were heated in a sealed bulb at $444^\circ C$ till the equilibrium state was reached. Its degree of dissociation at this temperature was found to be $22\% .$ The number of moles of hydrogen iodide present at equilibrium are

Consider the following equilibrium at $25^{\circ} \mathrm{C}$ $\mathrm{CuSO}_4.5 \mathrm{H}_2 \mathrm{O}{(\mathrm{s})} \rightleftharpoons \mathrm{CuSO}_4.3 \mathrm{H}_2 \mathrm{O}{(\mathrm{s})}+2 \mathrm{H}_2 \mathrm{O}{(\mathrm{g})}$ If this reaction takes place at two cities $\mathrm{A}$ and $\mathrm{B}$ having relative humidity $60 \%$ and $80 \%$ respectively. The vapour pressure of water at $25^{\circ} \mathrm{C}$ is $20 \mathrm{~mm} \mathrm{~Hg}$ and $\mathrm{K}_{\mathrm{P}}$ for the above reaction is $4 \times 10^{-2}(\mathrm{atm})^2$ at $25^{\circ} \mathrm{C}$ then $\mathrm{CuSO}_4.5 \mathrm{H}_2 \mathrm{O}$ acts as efflorescent in which city?

For the reaction $\mathrm{H}_2(\mathrm{~g})+\mathrm{CO}_2(\mathrm{~g}) \rightleftharpoons \mathrm{CO}(\mathrm{g})+\mathrm{H}_2 \mathrm{O}(\mathrm{g})$, If the initial concentration of $\left[\mathrm{H}_2\right]=\left[\mathrm{CO}_2\right]$ and $\mathrm{~x} \mathrm{~mol} / \mathrm{L}$ of hydrogen is consumed at equilibrium, the correct expression of $k_{\mathrm{p}}$ is

$20 \%$ of $\mathrm{N}_2 \mathrm{O}_4$ molecules are dissociated in a sample of gas at $27^{\circ} \mathrm{C}$ and 760 torn. Calculate the density of the equilibrium mixture.

Which oxide of nitrogen is the most stable?

What is the minimum $\mathrm{pH}$ necessary to cause a precipitate of ${Pb}({OH})_2\left({~K}_{{sp}}=1.2 \times 10^{-5}\right)$ to form in a $0.12\, \mathrm{M}\,\, {PbCl}_2$ solution ?

STATEMENT-1 : The endothermic reactions are favoured at lower temperature and the exothermic reactions are favoured at higher temperature.

STATEMENT-2 : When a system in equilibrium is disturbed by changing the temperature, it will tend to adjust itself so as to overcome the effect of change

For a weak electrolyte $\alpha_1$ and $\alpha_2$ are in ratio of $1: 2$, for a given concentration $k_{\mathrm{a}_1}=2 \times 10^{-4}$. What will be value of $\mathrm{k}_{\mathrm{a}_2}$ ?

Buffer capacity of a buffer solution is x, the volume of 1M added to 100 ml of this solution if the change of ${P^H}$ by 1 is

An aqueous solution contains an unknown concentration of $B{a^{2 + }}.$ When 50 mL of a 1 M solution of $N{a_2}S{O_4}$ is added, $BaS{O_4}$ just begins to precipitate. The final volume is 500 mL. The solubility product of $BaS{O_4}$ is $1 \times {10^{ - 10}}$. What is the original concentration of $B{a^{2 + }}?$

In $\mathrm{100}\;\mathrm{mL}$ of an aqueous $\mathrm{HCl}$ of $\mathrm{pH}\;1.0,\;900\;\mathrm{mL}$ of distilled water is added, the pH of the resultant solution becomes:

Which may be added to one litre of water to act as a buffer?

The equivalent conductance of $\frac{M}{{32}}$ solution of a weak monobasic acid is $8.0\;\mathrm{mhos}\;\mathrm{c}{\mathrm{m}^2}$ and at infinite dilution is $400\;\mathrm{mhos}\;\mathrm{c}{\mathrm{m}^2}.$ The dissociation constant of this acid is:

For the reaction $C(s) + C{O_2}(g)2\,\,CO(g)$ the partial pressure of $C{O_2}$ and are 2.0 and 4.0 atm resp, at equilibrium. The ${K_p}$ for the reaction is

Solution prepared by dissolving equal number of mole of $\mathrm{HOCl}\;\left( {{K_a} = 3.2 \times {{10}^{ - 8}}} \right)$ and $\mathrm{NaOCl}$ is a buffer of pH:

Which one of the molecular hydride acts as Lewis acid?

Which of the following mixture is a buffer solution?

Which of the following is Lewis acid?

The ionisation constant of an acid, $K_a$ is the measure of strength of an acid. The $K_a$ values of acetic acid, hypochlorous acid and formic acid are $1.74 \times 10^{-5}$, $3.0 \times 10^{-8}$ and $1.8 \times 10^{-4}$ respectively. Which of the following order of $\mathrm{pH}$ of $0.1 \mathrm{~mol}\,\mathrm{dm}^{-3}$ solutions of these acids is correct?

For an equilibrium $\mathrm{H}_2 \mathrm{O}(\mathrm{s}) \rightleftharpoons \mathrm{H}_2 \mathrm{O}(\mathrm{l})$ which of the following statements is true:

Assertion : ${pH}$ of hydrochloric acid solution is less than that of acetic acid solution of the same concentration.

Reason : In equimolar solutions, the number of titrable protons present in hydrochloric acid is less than that persent in acetic acid.

STATEMENT-1 : The equilibrium constant of the exothermic reaction at high temperature decreases.

STATEMENT-2 : Since $\ln \frac{K_2}{K_1}=\frac{\Delta H^{\circ}}{R}\left[\frac{1}{T_1}-\frac{1}{T_2}\right]$ and for exothermic reaction, $\Delta H^{\circ}=-$ ve and thereby; $\frac{K_2}{K_1} < 1$

The value of the equilibrium constant for the reaction: $2NO + {O_2} \rightleftharpoons 2N{O_2}$ is 0.25, then the value of equilibrium constant for $2N{O_2} \rightleftharpoons 2NO + {O_2}$ is