Physical Chemistry Questions

Which one of the following pairs of solution is not an acidic buffer?

If the equilibrium constant for ${\text{N}}_2(g)+{\text{O}}_2(g)\rightleftharpoons 2\text{NO}(g)$ is $K$, the equilibrium constant for $\frac{1}{2}{\text{N}}_2(g)+\frac{1}{2}{\text{O}}_2(g)\rightleftharpoons \text{NO}(g)$ will be:

The formation of the oxide ion, ${\text{O}}^{2-}(g)$, from oxygen atom requires first an exothermic and then an endothermic step as shown below:$\text{O}(g)+e^{-}⟶{\text{O}}^{-}(g);{\Delta }_f{H}^{\ominus }=-141{\text{kJ mol}}^{-1}$${\text{O}}^{-}(g)+e^{-}⟶{\text{O}}^{2-}(g);{\Delta }_f{H}^{\ominus }=+780{\text{kJ mol}}^{-1}$ Thus the process of formation of ${\text{O}}^{2-}$ in gas phase is unfavourable though ${\text{O}}^{2-}$ is isoelectronic with neon. It is due to the fact that:

Standard enthalpy of vapourisation ${\Delta }_{\text{vap}}{H}^{\circ }$ for water at $100^{\circ }\text{C}$ is $40.66\text{kJ/mol}$. The internal energy of vapourisation of water at $100^{\circ }\text{C}$ (in $\text{kJ/mol}$) is:

In which of the following reactions, standard reaction entropy change ($\Delta S^{\circ }$) is positive and standard Gibb’s energy change ($\Delta G^{\circ }$) decreases sharply with increasing temperature?

In a zero-order reaction for every $10^{\circ }$ rise of temperature, the rate is doubled. If the temperature is increased from $10^{\circ }\text{C}$ to $100^{\circ }\text{C}$, the rate of the reaction will become: