Question Bank Directory

Which one of the following statements is correct?

A reaction having equal energies of activation for forward and reverse reactions has

The rate constants $k_1$ and $k_2$ for two different reactions are $10^{16} e^{-2000/T}$ and $10^{15} e^{-1000/T}$, respectively. The temperature at which $k_1 = k_2$ is:

Mark the correct order of repulsion among the following according to the VSEPR theory.

For the reaction $A + B \rightarrow \text{products}$, it is observed that: (i) On doubling the initial concentration of A only, the rate of reaction is also doubled. (ii) On doubling the initial concentrations of both A and B, there is a change by a factor of 8 in the rate of the reaction. The rate of this reaction is given by:

Match List-I with List-II. **List-I (Compound)** A. $NH_3$ B. $BrF_5$ C. $XeF_4$ D. $SF_6$ **List-II (Shape/geometry)** I. Trigonal Pyramidal II. Square Planar III. Octahedral IV. Square Pyramidal

Identify the incorrect statement among the following:

The decomposition of phosphine ($\text{PH}_3$) on tungsten at low pressure is a first-order reaction. It is because the:

For a first-order reaction $A \rightarrow \text{Products}$, initial concentration of A is $0.1 \text{ M}$, which becomes $0.001 \text{ M}$ after $5 \text{ minutes}$. Rate constant for the reaction in $\text{min}^{-1}$ is

Which pair of the following compounds has one lone pair of electrons on the central atom?

The bromination of acetone that occurs in acid solution is represented by this equation: $\text{CH}_3\text{COCH}_3(aq) + \text{Br}_2(aq) \rightarrow \text{CH}_3\text{COCH}_2\text{Br}(aq) + \text{H}^+(aq) + \text{Br}^-(aq)$ These kinetic data were obtained for given reaction concentrations: | $[\text{CH}_3\text{COCH}_3]$ (M) | $[\text{Br}_2]$ (M) | $[\text{H}^+]$ (M) | Initial rate, disappearance of $\text{Br}_2$ ($\text{M s}^{-1}$) | | :---: | :---: | :---: | :---: | | $0.30$ | $0.05$ | $0.05$ | $5.7 \times 10^{-5}$ | | $0.30$ | $0.10$ | $0.05$ | $5.7 \times 10^{-5}$ | | $0.30$ | $0.10$ | $0.10$ | $1.2 \times 10^{-4}$ | | $0.40$ | $0.05$ | $0.20$ | $3.1 \times 10^{-4}$ | Based on these data, the rate equation is:

A first-order reaction has a rate constant of $2.303 \times 10^{-3} \text{ s}^{-1}$. The time required for $40 \text{ g}$ of this reactant to reduce to $10 \text{ g}$ will be [Given that $\log_{10} 2 = 0.3010$]

A compound that does not undergo $S_N1$ reaction with $\text{OH}^-$ is:

Which of the following species contains an equal number of $\sigma$ and $\pi$ bonds?

The given graph is a representation of the kinetics of a reaction. The $y$ and $x$ axes for zero and first-order reactions, respectively are:

What is the rate constant for a reaction if the time taken by the first-order decomposition of $\text{SO}_2\text{Cl}_2$ to decompose to $40\%$ is $560 \text{ seconds}$? [Given: $\log 2.5 = 0.3979$]

Mechanism of a hypothetical reaction $X_2 + Y_2 \rightarrow 2XY$ is given below: (i) $X_2 \rightleftharpoons X + X$ (fast) (ii) $X + Y_2 \rightarrow XY + Y$ (slow) (iii) $X + Y \rightarrow XY$ (fast) The overall order of the reaction will be:

For the reaction, $\text{N}_2\text{O}_5(g) \rightarrow 2\text{NO}_2(g) + \frac{1}{2}\text{O}_2(g)$ the value of the rate of disappearance of $\text{N}_2\text{O}_5$ is given as $6.25 \times 10^{-3} \text{ mol L}^{-1}\text{s}^{-1}$. The rate of formation of $\text{NO}_2$ and $\text{O}_2$ is given respectively as:

The unit of rate constant for a zero-order reaction is:

Which of the following expression is correct for the reaction given below? $2HI(g) \rightarrow H_2(g) + I_2(g)$