Consider the following

(A) 0.0025

(B) 500.0

(C) 2.0034

Number of significant figures in $A, B$ and $C$ respectively, are

Consider the following reaction

$$ A(g)+3 B(g) \longrightarrow 2 C(g) ; \Delta H^{\ominus}=-24 \mathrm{~kJ} $$

At $25^{\circ} \mathrm{C}$, if $\Delta G^{\ominus}$ of the reaction is -9 kJ , the standard entropy change (in $\mathrm{JK}^{-1}$ ) of the same reaction at same temperature is

One mole of $\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}(l)$ was completely burnt in oxygen to form $\mathrm{CO}_2(g)$ and $\mathrm{H}_2 \mathrm{O}(l)$. The standard enthalpy of formation $\left(\Delta_f H^{\ominus}\right)$ of $\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}(l), \mathrm{CO}_2(g)$ and $\mathrm{H}_2 \mathrm{O}(l)$ is $x, y$, $z \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. What is $\Delta_r H^{\ominus}\left(\right.$ in $\left.\mathrm{kJ} \mathrm{mol}^{-1}\right)$ for this reaction?

At $25^{\circ} \mathrm{C}, K_a$ of formic acid is $1.8 \times 10^{-4}$. What is the $K_b$ of $\mathrm{HCOO}^{-}$?