Observe the table given' showing volume of CO₂ obtained by reaction of CaCO₃ and dilute HCI after every minute. Answer the questions that follow:
Table showing volume of CO₂ at one minute interval by reaction of CaCO₃ with dilute HCI.

(a) What happens to rate of reaction with time?
(b) Why does CaCO₃ powder react faster than marble chips?
(c) What happens to rate of reaction if concentrated HCI is used?
d) In manufacture of NH₃ ,
\(\mathbf{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) 2 \rightleftharpoons \mathrm{NH}_{3}+\text { heat }\)
what is effect of pressure on rate of reaction?
(e) Why does rate of reaction becomes almost double for energy 10° rise in temperature?

Observe the following graphs and answer the questions based on these graphs.

(a) What is order of reaction shown in graph I?
(b) What is slope in graph II?
(c) How does t_1/2 varies with initial concentration in zero order reaction.
(d) If t_1/2 of first order reaction is 40 minute, what will be t _{99. 9 %} for first order reaction?
(e) What is t_1/2 of zero order reaction in terms of 'k'?

Chemical kinetics deals with rate of chemical reactions, how fast reactants get used up or how fast products are formed in the reaction. Differed chemical reactions have different speed. Rate of reaction depends upon concentration of reactants, temperature, pressure especially in gaseous reactions and presence of catalyst. Chemical reaction takes place as a results of collision between reacting molecules. The rate of reaction does not depend upon total number of coUisions rather it depends upon number of effective coUisions. In a redox reaction, if \(\mathbf{E}_{\text {cell }}^{\circ} \text { is }+\mathbf{v e}, \Delta \mathbf{G}^{\circ}\) will be -ve and 'K' equilibrium constant will be high i.e. products formed will be more than the reactants.
(a) k (The rate constant), (Activation Energy) Ea and 'A' (Arrhenius constant) are 3 x 10^-4 s^-1, 104.4 k.J mol^-1 and 6.0 x 10¹⁴ S^-1 respectively. What is value of 'k' when T \(\mathbf{T} \rightarrow \infty ?\)
(b) What is meant by activation energy?
(c) What does e^Ea/RT represent?
(d) If Fe 3 ⁺ + 2I^- \(\rightarrow\) Fe2 ⁺ + I₂ has E^o = 0.24V, what is the value of log K? What does value of 'K' indicate?
(e) What type of molecules undergo effective collisions?

Read the passage given below and answer the following questions :
For a first order reaction \(A \rightarrow \text { Products, } k=\frac{2.303}{t} \log \frac{a}{a-x}\) were a is the initial concentration of A and (a-x) is the concentration of A after time t. k is rate constant. Its value is constant at constant temperature for a reaction. The time in which half of the reactant is consumed is called half-life period. Half-life period of a first order reaction is constant. Its value is independent of initial concentration or any other external conditions.
In these questions (i-iv), a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
(i) Assertion : Rate of reaction doubles when concentration of reactant is doubled if it is a first order reaction.
Reason : Rate constant also doubles,

(ii) Assertion : Hydrolysis of ethyl acetate in presence of acid is a reaction of first order whereas in presence of alkali, it is a reaction of second order.
Reason : Acid only acts as a catalyst whereas alkali acts as one of the reactants.

(iii) Assertion : For a first -order reaction, the concentration of the reactant decreases exponentially with time.
Reason : Rate of reaction at any time depends upon the concentration of the reactant at that time.

(iv) Assertion : Half-life period for a first order reaction is independent of initial concentration of the reactant.
Reason : For a first order reaction, \(t_{1 / 2}=\frac{0.693}{k}\), where k is rate constant.

Read the passage given below and answer the following questions :
Decrease in concentration of reactant or increase in concentration of product per unit time is called rate of reaction. It is of two types:
(i) Instantaneous rate of reaction : Rate of change of concentration of reactant or product at a particular time is called instantaneous rate of reaction.
\(r_{\text {inst. }}=\frac{d C}{d t}\) 
where, dC = infinitely small change in concentration
dt = infinitely small change in time.
(ii) Average rate of reaction: Ratio of change in concentration and time required for the change is average rate of reaction.
\(r_{a v}=\frac{\Delta x}{\Delta t}=\frac{\text { Change in concentration }}{\text { Time required for the change }}\) 
For a reaction of the type, \(m_{1} A+m_{2} B \rightarrow n_{1} C+n_{2} D\) 
Rate of reaction is given as
\(-\frac{1}{m_{1}} \frac{d[A]}{d t}=-\frac{1}{m_{2}} \frac{d[B]}{d t}=+\frac{1}{n_{1}} \frac{d[C]}{d t}=+\frac{1}{n_{2}} \frac{d[D]}{d t}\) 
In these questions (i-iv), a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.

(i) Assertion : The kinetics of the reaction,\(m A+n B+p C \rightarrow m^{\prime} X+n^{\prime} Y+p^{\prime} Z\) obey the rate expression as \(\frac{d x}{d t}=k[A]^{m}[B]^{n}\) .
Reason : The rate of the reaction does not depend upon the concentration of C.
(ii) Assertion: Instantaneous rate of reaction is equal to dx/ dt.
Reason : It is the rate of reaction at any particular instant of time.
(iii) Assertion : For the reaction,\(R \mathrm{Cl}+\mathrm{NaOH} \rightarrow \mathrm{ROH}+\mathrm{NaCl}\) the rate of reaction is reduced to half on reducing the concentration of RCl to half.
Reason : The sate of reaction is represented by k[RCl].
(iv) Assertion : In rate law, unlike in the expression for equilibrium constants, the exponents for concentrations do not necessarily match the stoichiometric coefficients.
Reason: It is the mechanism and not the balanced chemical equation for the overall change that governs the reaction rate.

Read the passage given below and answer the following questions:
A reaction in which rate of reaction is independent of concentration of the reactants is called zero order reaction. Photochemical combination of hydrogen and chlorine to give hydrogen chloride is an example of zero order reaction. The rate constant of a zero order reaction is equal to the rate of reaction. The half life period of a zero order reaction is directly proportional to initial concentration of the reactant. For a zero order reaction, \(k=\frac{1}{t}\left\{[A]_{0}-[A]\right\}\) 
In these questions (i-iv), a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.

(i) Assertion : For a zero order reaction, plot of rate vs concentration will be a straight line parallel to concentration axis.
Reason : For a zero order reaction, rate is independent of concentration.
(ii) Assertion : Photochemical combination of hydrogen and chlorine to give hydrogen chloride is an example of zero order reaction.
Reason : The rate of reaction depends on the concentration of hydrogen and independent of concentration of chlorine.
(iii) Assertion : If in a zero order reaction, the concentration of the reactant is doubled, the half-life period is also doubled.
Reason : For a zero order reaction, the rate of reaction is independent of initial concentration
(iv) Assertion : In a reaction A -7 products, the concentration of the reactant is reduced to zero after a finite time.
Reason : The order of reaction is zero.

Read the passage given below and answer the following questions :
The following reaction, \(A_{(g)} \stackrel{\Delta}{\longrightarrow} P_{(g)}+Q_{(g)}+R_{(g)}\)  follows first order kinetics. The half-life period of this reaction is 69.3 s at 500°C. The gas A is enclosed in a container at 500°C and at a pressure of 0.4 atm
The following questions are multiple choice questions. Choose the most appropriate answer:
(i) The rat constant for the reaction is

(ii) The total pressure of the system after 230 s will be

(iii) The plot of ln[A] vs t will be

(iv) Which of the following is not an example of first order reaction?

Read the passage given below and answer the following questions :
The half-life of a reaction is the time required for the concentration of reactant to decrease by half, i.e.,

\([A]_{t}=\frac{1}{2}[A]\) 
For first order reaction,
\(t_{1 / 2}=\frac{0.693}{k}\)  this means t_1/2 is independent of initial concentration. Figure shows that typical variation of concentration of reactant exhibiting first order kinetics. It may be noted that though the major portion of the first order kinetics may be over in a finite time, but the reaction will never cease as the concentration of reactant will be zero only at infinite time
The following questions are multiple choice questions. Choose the most appropriate answer:
(i) A first order reaction has a rate constant k = 3.01 x 10^-3 is. How long it will take to decompose half of the reactant?

(ii) The rate constant for a first order reaction is 7.0x 10^-4 s^-1. If initial concentration of reactant is 0.080 M, what is the half life of reaction?

(iii) For the half-life period of a first order reaction, which one of the following statements is generally false?

(iv) The rate of a first order reaction is 0.04 mol L^-1 s^-1 at 10 minutes and 0.03 mol L^-1 s^-1 at 20 minutes after initiation. The half-life of the reaction is

Read the passage given below and answer the following questions :
In a reaction, the rates of disappearance of different reactants or rates of formation of different products may not be equal but rate of reaction at any instant of time has the same value expressed in terms of any reactant or product. Further, the rate of reaction may not depend upon the stoichiometric coefficients of the balanced chemical equation. The exact powers of molar concentrations of reactants on which rate depends are found experimentally and expressed in terms of 'order of reaction'. Each reaction has a characteristic rate constant depends upon temperature. The units of the rate constant depend upon the order of reaction.
The following questions are multiple choice questions. Choose the most appropriate answer :
(i) The rate constant of a reaction is found to be 3 x 10^-3 mol^-2 L ² sec^-1.The order of the reaction is

(ii) In the reaction \(A+3 B \rightarrow 2 C\) ,the rate of formation of C is

(iii) Rate of a reaction can be expressed by following rate expression, Rate = k[A]² [B], if concentration of A is increased by 3 times and concentration of B is increased by 2 times, how many times rate of reaction increases?

(iv) The rate of a certain reaction is given by,rate = k[H⁺]ⁿ . The rate increases 100 times when the pH changes from 3 to 1. The order (n) of the reaction is

Read the passage given below and answer the following questions :
Number of molecules which must collide simultaneously to give product is called molecularity. It is equal to sum of coefficients of reactants present in stoichiometric chemical equation. For reaction, \(m_{1} A+m_{2} B \rightarrow \text { Product }\) 
Molecularity = [m₁ + m₂ ]
In complex reaction each step has its own molecularity which is equal to the sum of coefficients of reactants present in a particular step. Molecularity is a theoretical property. Its value is any whole number. Number of concentration terms on which rate of reaction depends is called order of reaction or sum of powers of concentration terms present in the rate equation is called order of reaction.
If rate equation of reaction is : Rate = \(k \cdot C_{A}^{m_{1}} \cdot C_{B}^{m_{2}}\) 
Then order of reaction = m₁ + m₂
In simple reaction, order and molecularity are same. In complex reaction, order of slowest step is the order of over all reaction. This step is known as rate determining step. Order is an experimental property. Its value may be zero, fractional or negative.
The following questions are multiple choice questions. Choose the most appropriate answer:
(i) Higher order (> 3) reactions are rare due to

​​​​​​(ii) The molecularity of the reaction:
\(6 \mathrm{FeSO}_{4}+3 \mathrm{H}_{2} \mathrm{SO}_{4}+\mathrm{KClO}_{3} \rightarrow \mathrm{KCl}+3 \mathrm{Fe}_{2}\left(\mathrm{SO}_{4}\right)_{3}+3 \mathrm{H}_{2} \mathrm{O} \text { is }\)

(iii) Which of the following statements is false in the following?

(iv) The rate of the reaction \(A+B+C \rightarrow \text { products }\) , is given by \(r=-\frac{d[A]}{d t}=k[A]^{1 / 2}[B]^{1 / 3}[C]^{1 / 4}\) ,The order of the reaction is

Read the passage given below and answer the following questions:
A reaction is said to be of the first order if the rate of the reaction depends upon one concentration term only. For a first order reaction of the type A \(\rightarrow\) Products, the rate of the reaction is given as : rate = k[A]. The differential rate law is given as \(\frac{d A}{d t}=-k[A]\) .The integrated rate law : In \(\frac{[A]}{[A]_{0}}=-k t\) where [A] is the concentration of reactant left at time t and [A]_o is the initial concentration of the reactant, k is the rate constant.
The following questions are multiple choice questions. Choose the most appropriate answer :
(i) The unit of rate constant for a first order reaction is

(ii) Half-life period of a first order reaction is 10 min. Starting with initial concentration 12 M, the rate after 20 min is

(iii) For a first order reaction, (A) \(\rightarrow\) products, the concentration of A changes from 0.1 M to 0.025 M in 40 minutes. The rate of reaction when the concentration of A is 0.01 M, is

(iv) The half-life period of a 1^st order reaction is 60 minutes. What percentage will be left over after 240 minutes?

Read the passage given below and answer the following questions:
For the reaction: \(2 \mathrm{NO}_{(g)}+\mathrm{Cl}_{2(g)} \rightarrow 2 \mathrm{NOCl}_{(g)}\),  the following data were collected. All the measurements were taken at 263 K.

The following questions are multiple choice questions. Choose the most appropriate answer:
(i) The molecularity of the reaction is 

(ii) The expression for rate law is

(iii) The overall order of the reaction is

(iv) The value of rate constant is

Read the passage given below and answer the following questions :
The progress of the reaction, \(A \rightleftharpoons n B\) with time is represented in the following figure.

The following questions are multiple choice questions. Choose the most appropriate answer:
(i) What is the value of n?

(ii) Find the-value of the equilibrium constant

(iii) The initial rate of conversion of A will be

(iv) For the reaction,  if \(\frac{d[B]}{d t}=2 \times 10^{-4}\) , value of \(-\frac{d[A]}{d t}\) will be