AIEEE 2010 PYQ Mock Test

The standard enthalpy of formation of ${\text{NH}}_3$ is $-46.0{\text{kJ mol}}^{-1}$. If the enthalpy of formation of ${\text{H}}_2$ from its atoms is $-436{\text{kJ mol}}^{-1}$ and that of ${\text{N}}_2$ is $-712{\text{kJ mol}}^{-1}$, the average bond enthalpy of $\text{N}-\text{H}$ bond in ${\text{NH}}_3$ is:

The time for half life period of a certain reaction $\text{A}\to \text{products}$ is $1\text{hour}$. When the initial concentration of the reactant '$\text{A}$ ', is $2.0{\text{mol L}}^{-1}$, how much time does it take for its concentration to come from $0.50$ to $0.25{\text{mol L}}^{-1}$ if it is a zero order reaction?

A solution containing $2.675\text{g}$ of ${\text{CoCl}}_3\cdot 6{\text{NH}}_3$ (molar mass $=267.5{\text{g mol}}^{-1}$) is passed through a cation exchanger. The chloride ions obtained in solution were treated with excess of ${\text{AgNO}}_3$ to give $4.78\text{g}$ of $\text{AgCl}$ (molar mass $=143.5{\text{g mol}}^{-1}$). The formula of the complex is (At. Mass of $\text{Ag}=108\text{u}$):

Consider the reaction:${\text{Cl}}_2(aq)+{\text{H}}_2\text{S}(aq)\to \text{S}(s)+2{\text{H}}^{+}(aq)+2{\text{Cl}}^{-}(aq)$ The rate equation for this reaction is $\text{rate}=k[{\text{Cl}}_2][{\text{H}}_2\text{S}]$.Which of these mechanisms is/are consistent with this rate equation?(A) ${\text{Cl}}_2+{\text{H}}_2\text{S}\to {\text{H}}^{+}+{\text{Cl}}^{-}+{\text{Cl}}^{+}+{\text{HS}}^{-}$ (slow)${\text{Cl}}^{+}+{\text{HS}}^{-}\to {\text{H}}^{+}+{\text{Cl}}^{-}+\text{S}$ (fast)(B) ${\text{H}}_2\text{S}\rightleftharpoons {\text{H}}^{+}+{\text{HS}}^{-}$ (fast equilibrium)${\text{Cl}}_2+{\text{HS}}^{-}\to 2{\text{Cl}}^{-}+{\text{H}}^{+}+\text{S}$ (slow)

If $10^{-4}{\text{dm}}^3$ of water is introduced into a $1.0{\text{dm}}^3$ flask to $300\text{K}$, how many moles of water are in the vapour phase when equilibrium is established?(Given: Vapour pressure of ${\text{H}}_2\text{O}$ at $300\text{K}$ is $3170\text{Pa}$; $R=8.314{\text{J K}}^{-1}{\text{mol}}^{-1}$)