Assertion(A): For elementary reactions, the law of mass action and rate law expression are generally the same.

Reason(R): Molecularity of elementary reaction is always one.

Assertion(A): At very high temperatures (approaches to infinity) rate constant becomes equal to collision frequency.

Reason(R): The collision in which molecules collide with proper orientation is called ineffective collisions

Assertion(A): Base catalyzed hydrolysis of ethyl acetate is a first-order reversible reaction.

Reason(R): Order of reaction always depends on the stoichiometry of the reaction.

Assertion(A): The overall order of the reaction is the sum of the power of all the reactants in the rate expression.

Reason(R): There are many higher-order reactions.

For a reaction A $\to$B; Arrhenius equation is given as log_e k= 4 -$\frac{1000}{T}$; the activation energy in J/mol for the given reaction is-

For a reaction:-

${6\mathrm{H}}^{+}+ 5{\mathrm{Br}}^{-}+ \mathrm{Br}{\mathrm{O}}_3^{-}\to 3{\mathrm{Br}}_2+ 6{\mathrm{H}}_2\mathrm{O}$

lf rate of consumption of BrO${{}_3}^{-}$ is x mol ${\mathrm{L}}^{-1}{\mathrm{s}}^{-1}$. Then calculate the rate of formation of Br${}_2$:-

The half-life of 2 sample are 0.1 and 0.4 seconds respectively. Their concentrations are 200 and 50 respectively. The order of the reaction is : 

The rate constant for a first order reaction is $4.606\times {10}^{-3} s^{-1}$. The time required to reduce 2.0 g of the reactant to 0.2 g is:

An increase in the concentration of the reactants of a reaction leads to change in:

Consider the plots, given below, for the types of reaction

nA$\to$B+C

These plots respectively correspond to the reaction orders:

For a reaction $\frac{1}{2}A\to 2B$, rate of disappearance of 'A' is related to the rate of appearance of 'B' by the expression:

For a first order reaction $A\to P$, the temperature (T) dependent rate constant (k) was found to follow the equation log k= -(2000)$\frac{1}{T}+6.0$. The pre-exponential factor A and the activation energy $E_a$, respectively, are:

Plots showing the variation of the rate constant (K) with temperature (T) are given below. The plot that follows Arrhenius equation is:

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

The radionuclide ${}_{90}{}^{234}Th$ undergoes two successive $\beta$-decays followed by one $\alpha$-decay. the atomic number and the mass number respectively of the resulting radionucleide are:

A radioactive element has a half-life of 20 minute. How much time should elapse before the element is reduced to 1/8 its original value?

The half-life of  ⁹²U₂₃₈ against $\alpha$-decay is $4.5\times {10}^9$ year. The time taken in a year for the decay of 15/16 part of this isotope is :

A radioactive isotope has a half-life of 10 day. If today there are 125 g of it left, what was its original weight 40 day earlier?

Two radioisotopes P and Q of atomic weight 10 and 20 respectively are mixed in equal amount by weight. After 20 days, their weight ratio is found to be 1:4. Isotope P has a half-life of 10 day. The half-life of isotope Q is:

The rate constant of a reaction is $5.8 \mathrm{x} {10}^{-2} {\mathrm{s}}^{-1}$. The order of the reaction is : 

For a chemical reaction $\mathrm{A}\to$ product, the mechanism of the reaction postulated was as follows.

$\mathrm{A}\underset{{\mathrm{k}}_2}{\overset{{\mathrm{k}}_1}{\rightleftharpoons }}3\mathrm{B}\underset{\mathrm{R}.\mathrm{D}.\mathrm{S}}{\overset{{\mathrm{k}}_3}{\to }}{\mathrm{C}}_{\mathrm{}}$

If the reaction occured with individual rate constants k₁, k₂ and k₃, the activation energy for the overall reaction if the activation energies associated with these rate constants is : 

(Given: $$\begin{gathered} {\mathrm{E}}_{{\mathrm{a}}_1}=180 \mathrm{kJ} {\mathrm{mol}}^{-1} \\ {\mathrm{E}}_{{\mathrm{a}}_2}=90 \mathrm{kJ} {\mathrm{mol}}^{-1} \\ {\mathrm{E}}_{{\mathrm{a}}_3}=40 \mathrm{kJ} {\mathrm{mol}}^{-1} \end{gathered}$$)

The activation energy for a simple chemical reaction A $\to$ B is E_a in forward direction. The activation energy for reverse reaction :

3A $\to$ B + C

It would be a zero order reaction when :

If the rate of the reaction is equal to the rate constant, the order of the reaction is : 

The temperature dependence of rate constant (k) of a chemical reaction is written in terms of Arrhenius equation, k = Ae^-Ea/RT . Activation energy E_a of the reaction can be calculated by plotting : 

The half-life for a zero-order reaction having 0.02 M initial concentration of reactant is 100 s. The rate constant (in mol ${\mathrm{L}}^{-1} {\mathrm{s}}^{-1}$) for the reaction is

$$\begin{gathered} {\mathrm{CH}}_3{\mathrm{COOC}}_2{\mathrm{H}}_5 + {\mathrm{H}}_2\mathrm{O} \stackrel{{\mathrm{H}}^{+}}{\to } {\mathrm{CH}}_3\mathrm{COOH} + {\mathrm{C}}_2{\mathrm{H}}_2\mathrm{OH} \\ \mathrm{Ethyl} \mathrm{acetate} \mathrm{Acetic} \mathrm{acid} \mathrm{Ethyl} \mathrm{alcohol} \end{gathered}$$

The above reaction is an example of : 

What is the rate equation for reaction 2A+ B $\stackrel{}{\to }$ C if the order of the reaction is zero ?

For a certain reaction large fraction of molecules have energy more than the threshold energy, yet why the rate of reaction is very slow.It is due to improper: 

For a general reaction A $\to$ B, the plot of concentration of A v/s time is given in the figure. 
 

The slope of the curve is :