Directions: Each of these questions contains an Assertion followed by reason. Read them carefully and answer the question on the basis of following options. You have to select the one that best describes the two statements.

$\mathrm{Assertion}:$ $\mathrm{pH}$ of ammonium chloride solution is acidic.
$\mathrm{Reason}:$ Solution of a salt of weak base and strong acid is acidic.

Directions: Each of these questions contains an Assertion followed by reason. Read them carefully and answer the question on the basis of following options. You have to select the one that best describes the two statements.

$\mathrm{Assertion}:$ A buffer solution has a capacity to resist the change in $\mathrm{pH}$ value on addition of small amount of acid or base to it.
$\mathrm{Reason}:$ $\mathrm{pH}$ value of buffer solution does not change on dilution or on keeping for long.

Directions: Each of these questions contains an Assertion followed by reason. Read them carefully and answer the question on the basis of following options. You have to select the one that best describes the two statements.

$\mathrm{Assertion}:$ $\mathrm{pH}$ of blood is maintained inspite of acidic foods.
$\mathrm{Reason}:$ Acidity of foods is not so large to change the $\mathrm{pH}$ of blood.

Directions: Each of these questions contains an Assertion followed by reason. Read them carefully and answer the question on the basis of following options. You have to select the one that best describes the two statements.

$\mathrm{Assertion}:$ Aqueous solution of ${\mathrm{CuSO}}_4$ turns red litmus blue.
$\mathrm{Reason}:$ It gives basic solution on hydrolysis.

Directions: Each of these questions contains an Assertion followed by reason. Read them carefully and answer the question on the basis of following options. You have to select the one that best describes the two statements.

$\mathrm{Assertion}:$ $\mathrm{NaCl}$ solution in water will have higher $\mathrm{pH}$ than aqueous solution of ${\mathrm{Na}}_2{\mathrm{CO}}_3$

$\mathrm{Reason}:$ $\mathrm{NaCl}$ hydrolyses to give $\mathrm{HCl}$.

For the chemical equilibrium,

${\mathrm{CaCO}}_3\left(\mathrm{s}\right)\rightleftharpoons \mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$

$\mathrm{\Delta H}°$ can be determined from which of the following plots?

In which of the following reactions, the concentration of the product is higher than the concentration of reactant at equilibrium? ($\mathrm{K}=$ equilibrium constant).

Two moles of each reactant $\mathrm{A}$ and $\mathrm{B}$ are taken in a reaction flask. They react in the following manner,

$\mathrm{A}\left(g\right)+\mathrm{B}\left(g\right)\rightleftharpoons \mathrm{C}\left(g\right)+\mathrm{D}\left(g\right)$

At equilibrium, it was found that the concentration of $\mathrm{C}$ is triple to that $\mathrm{B}$. The equilibrium constant for the reaction is: