Physical Chemistry PYQ — Page 20

If uncertainty in position and momentum are equal, then uncertainty in velocity is

Which of the following are not state functions? (I) $q+W$ (II) $q$ (III) $W$ (IV) $H-T S$

Percentage of free space in a body centred cubic unit cell is

For the gas phase reaction, $\mathrm{PCl}_5(\mathrm{~g}) \rightleftharpoons \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2(\mathrm{~g})$ Which of the following conditions is correct?

The relative reactivities of acyl compounds towards nucleophilic substitution are in the order of

The bromination of acetone that occurs in acid solution is represented by this equation $\mathrm{CH}_3 \mathrm{COCH}_3(\mathrm{aq})+\mathrm{Br}_2(\mathrm{aq}) \rightarrow \mathrm{CH}_3 \mathrm{COCH}_2 \mathrm{Br}(\mathrm{aq})+\mathrm{H}^{+}(\mathrm{aq})+\mathrm{Br}^{-}(\mathrm{aq})$ These kinetic data were obtained for given reaction concentrations Initial concentrations, M  Based on these data, the rate equation is

Equimolar solutions of the following were prepared in water separately. Which one of the solutions will record the highest $\mathrm{pH}$ ?

If uncertainty in position and momentum are equal, then uncertainty in velocity is

The dissociation equilibrium of a gas $\mathrm{AB}_2$ can be represented as, $2 \mathrm{AB}_2(\mathrm{~g}) \rightleftharpoons 2 \mathrm{AB}(\mathrm{g})+\mathrm{B}_2(\mathrm{~g})$. The degree of dissociation is ' $\mathrm{x}$ ' and is small compared to 1. The expression relating the degree of dissociation $(\mathrm{x})$ with equilibrium constant $K_P$ and total pressure $\mathrm{P}$ is

If a gas expands at constant temperature, it indicates that

In DNA, the complimentary bases are

The rate constants $\mathrm{k}_1$ and $\mathrm{k}_2$ for two different reactions are $10^{16} \cdot \mathrm{e}^{-2000 / T}$ and $10^{15} \cdot \mathrm{e}^{-1000 / T}$ respectively. The temperature at which $\mathrm{k}_1=\mathrm{k}_2$ is

The following equilibrium constant are given: $\begin{aligned} \mathrm{N}_2+3 \mathrm{H}_2 & \rightleftharpoons 2 \mathrm{NH}_3 ; \mathrm{K}_1 \\ \mathrm{~N}_2+\mathrm{O}_2 & \rightleftharpoons 2 \mathrm{NO} ; \mathrm{K}_2 \\ \mathrm{H}_2+1 / 2 \mathrm{O}_2 & \rightleftharpoons \mathrm{H}_2 \mathrm{O} ; \mathrm{K}_3 \end{aligned}$ The equilibrium constant for the oxidation of $\mathrm{NH}_3$ by oxygen to give $\mathrm{NO}$ is:

The equilibrium constant of the reaction: $\mathrm{Cu}_{(s)}+2 \mathrm{Ag}_{(a q)}^{+} \rightarrow \mathrm{Cu}_{(a q)}^{2+}+2 \mathrm{Ag}_{(s)}$ $\mathrm{E}^{\mathrm{o}}=0.46 \mathrm{~V}$ at $298 \mathrm{~K}$ is:

Consider the following sets of quantum numbers: \(\begin{array}{|c|c|c|c|c|} \hline & n & l & m & s \\ \hline \text {(i) } & 3 & 0 & 0 & +1 / 2 \\ \text {(ii) } & 2 & 2 & 1 & +1 / 2 \\ \text {(iii) } & 4 & 2 & -2 & -1 / 2 \\ \text {(iv) } & 1 & 0 & -3 & -1 / 2 \\ \text {(v) } & 3 & 2 & 3 & +1 / 2 \\ \hline \end{array}\) Which of the following sets of quantum number is not possible?

The number of moles $\mathrm{KMnO}_4$ that will be needed to react with one mole of sulphite ion in acidic solution is:

A steady current of $1.5 \mathrm{amp}$ flows through a copper voltameter for 10 minutes. If the electrochemical equivalent of copper is 30 $\times 10^{-5} \mathrm{~g}$ coulomb $^{-1}$, the mass of copper deposited on the electrode will be.

Calculate the $\mathrm{pOH}$ of a solution $25^{\circ} \mathrm{C}$ that contains $1 \times 10^{-10} \mathrm{M}$ of hydronium ions i.e. $\mathrm{H}_3 \mathrm{O}^{+}$:

Concentrated of aqueous sulphuric acid is $98 \% \mathrm{H}_2 \mathrm{SO}_4$ by mass and has a density of $1.80 \mathrm{~g} \mathrm{~mL}^{-1}$ Volume of acid required to make one litre of $0.1 \mathrm{M} \mathrm{H}_2 \mathrm{SO}_4$ solution is:

Consider the following reactions: (i) $\mathrm{H}_{(a q)}^{+}+\mathrm{OH}_{(a q)}^{-} \rightarrow \mathrm{H}_2 \mathrm{O}_{(\mathrm{i})}, \Delta \mathrm{H}$ $=-\mathrm{X}_1 \mathrm{~kJ} \mathrm{~mol}^{-1}$ (ii) $\mathrm{H}_{2(a q)}+\frac{1}{2} \mathrm{O}_{2(a q)} \rightarrow \mathrm{H}_2 \mathrm{O}_{(\mathrm{I})} \Delta \mathrm{H}$ $=-\mathrm{X}_2 \mathrm{~kJ} \mathrm{~mol}^{-1}$ (iii) $\mathrm{CO}_{2(\mathrm{~g})}+\mathrm{H}_{2(g)} \rightarrow \mathrm{CO}_{(g)}+\mathrm{H}_2 \mathrm{O}, \Delta \mathrm{H}$ $=-\mathrm{X}_3 \mathrm{~kJ} \mathrm{~mol}^{-1}$ (iv) $\mathrm{C}_2 \mathrm{H}_{2(g)}+\frac{5}{2} \mathrm{O}_{2(g)} \rightarrow 2 \mathrm{CO}_{2(g)}+\mathrm{H}_2 \mathrm{O}_{(i) \text {, }}$ $\Delta \mathrm{H}=+\mathrm{X}_4 \mathrm{~kJ} \mathrm{~mol}^{-1}$ Enthalpy of formation of $\mathrm{H}_2 \mathrm{O}_{(l)}$ is:

Given that bond energies of $\mathrm{H}-\mathrm{H}$ and $\mathrm{Cl}-\mathrm{Cl}$ are $430 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $240 \mathrm{~kJ}$ $\mathrm{mol}^{-1}$ respectively and $\Delta \mathrm{H}_{\mathrm{f}}$ for $\mathrm{HCl}$ is $-\mathrm{kJ}$ $\mathrm{mol}^{-1}$, bond enthalpy of $\mathrm{HCl}$ is:

0.5 molal aqueous solution of a weak acid $(\mathrm{HX})$ is $20 \%$ ionised. If $\mathrm{K}_f$ for water is $1.86 \mathrm{Kg} \mathrm{mol}^{-1}$, the lowering in freezing point of the solution is:

If $60 \%$, of a first order reaction was completed in 60 minutes, $50 \%$ of the same reaction would be completed in approximately: $$ (\log 4=0.60, \log 5=0.69) $$

The reaction of hydrogen and iodine monochloride is given as: $\mathrm{H}_{2(g)}+2 \mathrm{ICl}_{(g)} \rightarrow 2 \mathrm{HCl}_{(g)}+\mathrm{I}_{2(g)}$ This reaction is of first order with respect to $\mathrm{H}_{2(g)}$ and $\mathrm{lCl}_{(g)+}$ following mechanisms were proposed Mechanism A: $\mathrm{H}_{2(g)}+2 \mathrm{ICl}_{(g)} \rightarrow 2 \mathrm{HCl}_{(g)}+\mathrm{H}_{2(g)}$ Mechanism B: $\begin{aligned} & \mathrm{H}_{2(g)}+\mathrm{ICl}_{(g)} \rightarrow \mathrm{HCl}_{(g)}+\mathrm{HI}_{(g)} \text { :slow } \\ & \mathrm{Hl}_{(g)}+\mathrm{lCl}_{(g)} \rightarrow \mathrm{HCl}_{(g)}+\mathrm{l}_{2(g)} \text {; fast } \end{aligned}$ Which of the above mechanism(s) can be consistent with the given information about the reaction?