In the reaction A(g) + 2B(g) ⇌ 2C(g) + D(g), the initial concentration of B is twice that of A and, at equilibrium, the concentrations of A and D are equal. The value of the equilibrium constant will be:

1.	4	2.	16
3.	2	4.	1

The number of ${\mathrm{H}}^{\oplus }$ ions present in 1 ml of a solution whose pH= 4 , is given as:

($N_A=$ $Avogadro\text{'}s$ $number$)

1. ${10}^{-7}{N}_A$

2. ${10}^{-8}{N}_A$

3. ${10}^{-16}{N}_A$

4. ${10}^{-14}{N}_A$

If the pH of an acidic buffer is 5.7 and ${\mathrm{pK}}_{\mathrm{a}}$ is 5 then the ratio of $\frac{\left[\mathrm{Salt}\right]}{\left[\mathrm{Acid}\right]}$ will be:

Assertion: At equilibrium, ${\mathrm{K}}_{}={\mathrm{Q}}_{\mathrm{c}}.$

Reason: When ${\mathrm{K}}_{\mathrm{c }}>\hspace{0.17em}{\mathrm{Q}}_{\mathrm{c}},$ the reaction mainly goes in the forward direction.

Given below are two statements: 

The concentration of $\left[{\mathrm{H}}^{+}\right]$ ion in a solution containing 0.1 M HCN and 0.2 M NaCN will be:

(${\mathrm{K}}_{\mathrm{a}}$ for HCN = $6.2\times {10}^{-10}$)

1. 3.1$\times {10}^{10}$

2. $6.2\times {10}^5$

3.$$ $6.2\times {10}^{-10}$

4. $3.1\times {10}^{-10}$

For the following reaction, 
 H$$₂(g)+I₂(g)⇌2HI(g) $at$ $250°C,$

The effect on the state of equilibrium on doubling the volume of the system will be:

Reaction quotient for the reaction, ${\mathrm{N}}_2\left(\mathrm{g}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)\rightleftharpoons 2{\mathrm{NH}}_3\left(\mathrm{g}\right)$ is given by , $\mathrm{Q}$ $=$ $\frac{{\left[{\mathrm{NH}}_3\right]}^2}{\left[{\mathrm{N}}_2\right]{\left[{\mathrm{H}}_2\right]}^3}$ .The reaction will proceed from right to left if K_c value is:

An acid buffer solution can be prepared by mixing the solutions of:

1. Sodium chloride and sodium hydroxide

2. Sulphuric acid and sodium sulphate

3. Ammonium chloride and ammonium nitrate

4. Ammonium acetate and acetic acid

The basic buffer solution among the following is: 

1. ${\mathrm{NH}}_4\mathrm{Cl}+{\mathrm{NH}}_4\mathrm{OH}$

2. $\mathrm{NaCl}+\mathrm{NaOH}$

3. ${\mathrm{NH}}_4\mathrm{Cl}+{\mathrm{CH}}_3\mathrm{COOH}$

4. ${\mathrm{CH}}_3\mathrm{COONa}+{\mathrm{CH}}_3\mathrm{COOH}$