Chemical Kinetics · Chemistry · COMEDK

The order of a reaction $\mathrm{W}+\mathrm{X} ---- \rightarrow \mathrm{Y}+\mathrm{Z}$ with respect to W is 3 and with respect to X is 1. If the concentrations of both W and X are tripled, the rate of reaction will increase by _________ times.

The decomposition of $\mathrm{PH}_3$ follows first order kinetics. The time required for $3 / 4^{\text {th }}$ of $\mathrm{PH}_3$ to decompose is 75.76 s . Calculate the fraction of original amount of $\mathrm{PH}_3$ which will remain after 2.0 minutes.

Choose the correct statement.

During a chemical reaction $\mathrm{X} \rightarrow \mathrm{Y}$, the rates of reaction starting with initial concentrations of X as $4.0 \times 10^{-3} \mathrm{M}$ and $2.0 \times 10^{-3} \mathrm{M}$ are $4.8 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} / \mathrm{s}$ and $1.2 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} / \mathrm{s}$ respectively. What is the order of reaction with respect to X ?

The hydrogenation of Ethyne is carried out at 600 K . The same reaction when carried out in presence of a catalyst maintaining the same rate constant, the temperature required is only 400 K . If the catalyst lowers the Activation energy of the reaction by $20 \mathrm{~kJ} / \mathrm{mol}$, what is the value of $\mathrm{E}_{\mathrm{a}}$ ?

The time needed for completion of $80 \%$ is $y$ times the half-life period of a first order reaction. What is the value of $y$ ?

Which one of the following is incorrect?

(i) and (ii) are 2 chemical reactions carried out at TK.

(i). $\mathrm{X} \rightarrow \mathrm{Y}+\mathrm{W}$ with $\mathrm{k}_1$ as rate constant.

(ii). $\mathrm{X} \rightarrow \mathrm{Z}+\mathrm{W}$ with $k_2$ as rate constant.

The Activation energy for reaction (ii) is 3 times that of reaction (i). What is the expression for $k_1$ ?

The rate constant for a zero order reaction $\mathrm{A} \rightarrow \mathrm{B}+\mathrm{C}$ is $6.0 \times 10^{-3} \mathrm{molL}^{-1} \mathrm{~s}^{-1}$. What would be the time taken for the initial concentration of A to decrease from 0.2 M to 0.024 M ?

Two statements, One Assertion (A) and the other Reason (R) are given. Choose the right option.

Assertion: The rate constant $(\mathrm{k})$ for a chemical reaction gets nearly doubled for a $10^0$ rise in temperature.

Reason: The number of bimolecular collisions between reactant molecules increase with increase in temperature

Two chemical reactions of the same order have equal Frequency factor value. Their Activation energies differ by $26.8 \mathrm{~kJ} / \mathrm{mol}$. At 300 K if $k_2=x k_1$ find the value of $x$.

For a given reaction of the type $\frac{3}{5} X(a q) \rightarrow \frac{1}{2} Y(a q)+Z(g)$, the correct expression for the rate of disappearance of $X$ with reference to $Y$ is ___________

$\mathrm{X} \rightarrow 2 \mathrm{Y}$ is a first order reaction where $1.0 \mathrm{~mol} / \mathrm{L}$ of the reactant yields $0.4 \mathrm{~mol} / \mathrm{L}$ of Y in 200 minutes. Calculate the half-life period of the reaction in minutes.

The following results were obtained during study of the reaction $2 \mathrm{NO}(\mathrm{g})+\mathrm{Cl}_2(\mathrm{~g}) \rightarrow 2 \mathrm{NOCl}(\mathrm{g})$. Determine the value of $[\mathrm{X}]$ in $\mathrm{mol} / \mathrm{L}$

Experiment	[NO] mol / L	[Cl$_2$] mol / L	Initial rate of formation. [NOCl] mol / L / min
I	0.2	0.2	$6.0 \times 10^{-3}$
II	0.2	0.4	$2.4 \times 10^{-2}$
III	0.4	0.2	$1.2 \times 10^{-2}$
IV	X	0.6	$1.35 \times 10^{-1}$

For a given reaction, ,$$\mathrm{X}(\mathrm{g})+\mathrm{Y}(\mathrm{g} \rightarrow \mathrm{Z}(\mathrm{g})$$, the order of reaction with respect to $$\mathrm{X}$$ and $$\mathrm{Y}$$ are $$\mathrm{m}$$ and $$\mathrm{n}$$ respectively. If the concentration of $$\mathrm{X}$$ is tripled and that of $$\mathrm{Y}$$ is decreased to one third, what is the ratio between the new rate to the original rate of the reaction?

For a reaction $$5 X+Y \rightarrow 3 Z$$, the rate of formation of $$Z$$ is $$2.4 \times 10^{-5} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$ Calculate the average rate of disappearance of $$\mathrm{X}$$.

In the presence of a catalyst at a given temperature of $$27^{\circ} \mathrm{C}$$, the Activation energy of a specific reaction is reduced by $$100 \mathrm{~J} / \mathrm{mol}$$. What is the ratio between the rate constants for the catalysed $$(\mathrm{k}_2)$$ and uncatalysed $$(\mathrm{k}_1)$$ reactions?

The following data was recorded for the decomposition of XY compound at 750K

[XY] mol / L	Rate of decomposition of XY mol / L s
0.4	$$5.5\times10^{-7}$$
0.8	$$22.0\times10^{-7}$$
1.2	$$49.5\times10^{-7}$$

What is the order of reaction with respect to decomposition of XY?

The Activation energy for the reaction $$A \rightarrow B+C$$, at a temperature $$\mathrm{TK}$$ was $$0.04606 \mathrm{~RT} \mathrm{~J} / \mathrm{mol}$$. What is the ratio of Arrhenius factor to the Rate constant for this reaction?

The temperature $$(\mathrm{T})$$ and rate constant $$(\mathrm{k})$$ for a first order reaction $$\mathrm{R} \rightarrow \mathrm{P}$$, was found to follow the equation $$\log \mathrm{k}=-(2000) \frac{1}{\mathrm{~T}}+8.0$$. The pre-exponential factor '$$\mathrm{A}$$' and activation energy $$\mathrm{E}_{\mathrm{a}}$$, respectively are: [Given: $$\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$]

Given below a first order reaction in the gas phase

$$\mathrm{A}(\mathrm{g}) \rightarrow \mathrm{B}(\mathrm{g})+\mathrm{C}(\mathrm{g})$$

If the initial pressure of the system is $$\mathrm{P}_{\mathrm{i}}$$ and the total pressure at $$\mathrm{t}$$ seconds is $$\mathrm{P}_{\mathrm{t}}$$, the rate constant $$\mathrm{k}$$ for the reaction is:

For the reaction, $$\mathrm{A}+3 \mathrm{~B} \rightarrow 2 \mathrm{C}+\mathrm{D}$$, the concentration of $$\mathrm{A}$$ changes from 0.0150 to 0.0125 in 1 minute. The rate of formation of $$\mathrm{C}$$ in $$\mathrm{mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}$$ is:

The rate of appearance of bromine is related to the disappearance of bromide ion in the equation given below is:

$$\mathrm{BrO}_3^{-} \text {(aq) }+5 \mathrm{Br}^{-} \text {(aq) }+6 \mathrm{H}^{+} \rightarrow 3 \mathrm{Br}_2(\mathrm{l})+3 \mathrm{H}_2 \mathrm{O}(\mathrm{l})$$

The half-life for a zero order reaction is

The time required for $$80 \%$$ of a first order reaction is "$$y$$" times the half-life period of the same reaction. What is the value of "$$y$$"?

The rate constant for the reaction $$\mathrm{A} \rightarrow \mathrm{B}+\mathrm{C}$$ at $$500 \mathrm{~K}$$ is given as $$0.004 \mathrm{~s}^{-1}$$. At what temperature will the rate constant become $$0.014 \mathrm{~s}^{-1}$$ ? $$\mathrm{E}_{\mathrm{a}}$$ for the reaction is $$18.231 \mathrm{~kJ}$$.

For the reaction $$\mathrm{Cl}_{2(\mathrm{~g})}+2 \mathrm{NO}_{(\mathrm{g})} \rightarrow 2 \mathrm{NOCl}_{(\mathrm{g})}$$, the following data was obtained:

Experiment No.	Initial concentration of $$\mathrm{Cl_2}$$ ($$\mathrm{M}$$)	Initial concentration of $$\mathrm{NO}$$ ($$\mathrm{M}$$)	Initial reaction rate ($$\mathrm{M}$$/min)
I	0.15	0.15	0.60
II	0.30	0.15	1.20
III	0.15	0.3	2.40
IV	0.25	0.25	2.78

Identify the order of the reaction with respect to $$\mathrm{Cl}_2, \mathrm{NO}$$ and the value of Rate constant.

Given below are 4 graphs [A], [B], [C] and [D]

Identify the 2 graphs that represent a Zero order reaction?

A given chemical reaction is represented by the following stoichiometric equation.

$$3 X+2 Y+\frac{5}{2} Z \rightarrow P_1+P_2+P_3$$

The rate of reaction can be expressed as _________.

COMEDK 2023 Morning Shift

How much faster would a reaction proceed at $$25^{\circ} \mathrm{C}$$ than at $$0^{\circ} \mathrm{C}$$ if the activation energy is $$65 \mathrm{~kJ}$$?

At $$300 \mathrm{~K}$$, the half-life period of a gaseous reaction at an initial pressure of $$40 \mathrm{~kPa}$$ is 350 s. When pressure is $$20 \mathrm{~kPa}$$, the half-life period is 175 s. What is the order of the reaction?

COMEDK 2023 Morning Shift

For a reaction, $$2 A+B \longrightarrow$$ products, If concentration of $$B$$ is kept constant and concentration of $$A$$ is doubled then rate of reaction is

COMEDK 2023 Morning Shift

A first order reaction proceeds to $$90 \%$$ completion. What will be the approximate time taken for $$90 \%$$ completion in relation to $$t_{1 / 2}$$ of the reaction?

For a reaction of the type, $$2 \mathrm{X}+\mathrm{Y} \rightarrow \mathrm{A}+\mathrm{B}$$, the following is the data collected:

Experiment	$$\mathrm{[X]}$$	$$\mathrm{[Y]}$$	Initial rate of formation of A
1	0.2	0.2	$$12.0\times10^{-3}$$
2	0.6	0.4	$$\mathrm{14.4\times10^{-2}}$$
3	0.6	0.8	$$5.76\times10^{-1}$$
4.	0.8	0.2	$$\mathrm{4.8\times10^{-2}}$$

What is the overall order of the reaction?

Match the details given in Column I with those given in Column II

S.No.	Column I	S.No.	Column II
A	For complex reactions order is determined by	P	Rate of reaction.
B	For Zero order reaction unit of $\mathrm{k}$ is same as that of	Q	Slope $$=k/2.303$$
C	Mathematical expression which gives relationship between rate of reaction and concentrations of reactants is called	R	Slowest rate determining step.
D	For a first order reaction plot of $$\mathrm{\log \left[R_0\right] /[R]}$$ vs time gives	S	Rate law.

Given below are graphs showing the variation in velocity constant with temperature on Kelvin scale. Identify the graph which represents Arrhenius equation.

The rate constant for a First order reaction at $$560 \mathrm{~K}$$ is $$1.5 \times 10^{-6}$$ per second. If the reaction is allowed to take place for 20 hours, what percentage of the initial concentration would have converted to products?