Electrochemistry and chemical kinetics - class-XII
Description: electrochemistry and chemical kinetics | |
Number of Questions: 85 | |
Created by: Kalki Agrawal | |
Tags: chemistry electrochemistry and chemical kinetics chemical kinetics |
Rate constant in case of first order reaction is :
Fill in the blanks by choosing the correct option;
Order of the reaction is the $X$ of the powers to which concentration terms are raised in experimentally determined rate equation. The unit of first order rate constant is $Y$. The unit of first order rate constant when concentration is measured in terms of pressure and time in minutes is $Z$.
Match the rate law given in column I with the dimensions of rate constant given in column II and mark the appropriate choice.
Column I | Column II |
---|---|
(A) $Rate = k[NH _{3}]^{0}$ | (i) $mol\ L^{-1} s^{-1}$ |
(B) $Rate = k[H _{2}O _{2}][I^{-}]$ | (ii) $L\ mol^{-1} s^{-1}$ |
(C) $Rate = k[CH _{3}CHO]^{3/2}$ | (iii) $s^{-1}$ |
(D) $Rate = k[C _{2}H _{5}Cl]$ | (iv) $L^{1/2} mol^{-1/2} s^{-1}$ |
For the second order reaction, concentration $(x)$ of the product at time $t$ starting with initial concentration $[A] _0$ is:
Units of rate constant of a first order reaction is :
A gaseous reaction, $A _{2}\left ( g \right )\rightarrow B\left ( g \right )+\frac{1}{2}\left ( g \right )$
Show increase in pressure from 40 mm to 120 mm in 5 minutes. the rate of disappearance of$A _{2}$ is ?
Consider the reaction $2A+B$ $\rightarrow$products,when the concentration of a alone was doubled, the half-life of the reaction did not change.When the concentration of B alone was double,the rate was not altered.The unit of rate constant for this reaction is
For the reaction $A\rightarrow C+D$, the initial concentration of $A$ is $1000 M$. After $10^{2} sec$ concentration of $A$ is $100\ M$. The rate constant of the reaction has the numerical value of $9.0$. What is the unit of the reaction rate constant?
The second order rate constant is usually expressed as :
The unit of rate constant obeying the rate expression, $r=k{ \left[ A \right] }{ \left[ B \right] }^{ { 2 }/{ 3 } }$ is:
For the second order reaction, if the concentration of reactant changes from $0.08M$ to $0.04M$ in 10 minutes. Calculate the time at which concentration of reactant becomes $0.01M$.
For a second order reaction rate at a particular time is $x$. Ifthe initial concentration is trapled, the rate will becomes?
The given reaction
$2FeCl _{3}+SnCl _{2}\rightarrow 2FeCl _{2}+SnCl _{4}$
Is an example of:
The rate constant for forward and backward reaction of hydrolysis of ester are $1.1\times 10^{-2}$ and $1.5\times 10^{-3}$ per minute respectively.
The dimensions of rate constant of a second order reaction involves:
Which is not true for a second order reaction ?
For a second order reaction rate at a particular time is $X$. If the initial concentration is tripled, the rate will become:
Which of the following statements is incorrect?
The rate of solvolysis of tert-butyl bromide will be maximum in which of the following solvents?
The inversion of cane sugar to produce glucose and fructose is represented by the reaction
${ C } _{ 12 }{ H } _{ 22 }{ O } _{ 11 }+{ H } _{ 2 }O\quad \xrightarrow { { H }^{ + } } { C } _{ 6 }{ H } _{ 12 }{ O } _{ 6 }+{ C } _{ 6 }{ H } _{ 12 }{ O } _{ 6 }$
The reaction is:
Units of the rate constant of first and zero order reactions in terms of molarity M unit are respectively:
The unit of rate constant obeying the rate expression $r=K[A]^{1}[B]^{2/3}$ is:
The reaction, $2A+ B \rightarrow$ Products, follows the mechanism:
$2A \leftrightharpoons A _2$ (at equilibrium)
$A _2 + B \rightarrow$ Products (slow)
The order of the reaction is:
For the elementary reaction 2A $\rightarrow $ C ,the concentration of A after 30 minutes was found to be 0.01 mole/lit. If the rate constant of the reaction is $2.5 \times 10^{-2}$ lit mole$^{-1}$ sec$^{-1}$. The rate of the reaction at 30 minutes is:
The specific rate of a reaction is $1.51 \times10^{-4}$ lit mole$^{-1}$ sec$^{-1}$. If the reaction is commenced with 0.2 mole lit$^{-1}$ of the reactant, the initial rate of the reaction in mole lit$^{-1}$ sec$^{-1}$ is:
Read the following table and chose the appropriate option
Rate equation | Units of K |
---|---|
I) rate $=$ k[A] | a) mol lit$^{-1}$ sec $^{-1}$ |
II) rate $=$ k[A][B] | b) mol$^{-2}$ lit$^{2}$ sec $^{-1}$ |
III) rate $=$ k[A][B]$^2$ | c) sec $^{-1}$ |
IV) rate $=$ k | d) lit mol$^{-1}$ sec $^{-1}$ |
Identify the reaction order from each of the following rate constants.
(i) $k=2.3 \times 10^{-5} L \quad mol^{-1} \quad s^{-1}$
(ii) $k=3 \times 10^{-4} \quad s^{-1}$
Units of rate constant for the first and zero order reactions in terms of molarity M units are respectively:
Consider the reaction, $2A + B \rightarrow$ Products, When concentration of B alone was doubled, the rate did not change. When the concentration of A alone was doubled, the rate increased by two times. The unit of rate constant for this reaction is:
The following mechanism has been proposed for the reaction of $NO$ with $\displaystyle Br _{2}$ to form $NOBr$
$NO(g)+Br _{2}(g)\rightleftharpoons NOBr _{2}(g)$
If the second step is the rate determining step,the order of the reaction with respect to $NO(g)$ is:
Taking the reaction $x+2y\rightarrow$ prodcuts, to be of second order, which of the following are the rate law expressions for the reaction :
(I) $\cfrac{dx}{dt}=K[x][y]$ (II) $\cfrac{dx}{dt}=K[x]{[y}]^{2}$
(III) $\cfrac{dx}{dt}=k{[x]}^{2}$ (IV) $\cfrac{dx}{dt}=K[x]+K{[y]}^{2}$
The rate of formation of ${SO} _{3}$ in the reaction $2{SO} _{2}+{O} _{2}\rightarrow 2{SO} _{3}$ is $100g{min}^{-1}$. Hence, rate of disappearance of ${O} _{2}$ is
Reaction $A+B\longrightarrow C+D$ follows rate law, $r=k{ \left[ A \right] }^{ 1/2 }{ \left[ B \right] }^{ 1/2 }$ starting with $1M$ of $A$ and $B$ each. What is the time taken for concentration of $A$ become $0.1M$?
[Given $2.303\times { 10 }^{ -2 }sec^{ -1 }$].
The reaction, $CH _3COOC _2H _5+NaOH\rightarrow CH _3COONa+C _2H _5OH$ is:
For the reaction: $2NO+Cl _2\rightarrow 2NOCl$, the following mechanism was proposed on the basis of experimental observation.
$NO+Cl _2\overset {Fast}{\rightleftharpoons}NOCl _2$
$NOCl _2+NO\xrightarrow {Slow}2NOBr$
The order of reaction is:
The unit of rate constant for a given reaction is $M^{1-n}L^{n-1}t^{-1}$ where n is order of reaction.
A 22.4 litre flask contains 0.76 mm of ozone at $25^oC$. Calculate:
(i) the concentration of oxygen atom needed so that the reaction, $O+O _3\rightarrow 2O _2$ having rate constant equal to $1.5\times 10^7$ litre $mol^{-1} sec^{-1}$ can proceed with a rate of 0.15 mol $litre^{-1} sec^{-1}$
(ii) the rate of formation of oxygen under this condition.
The unit and value of rate constant and that of rate of reaction are same for:
The rate constant of $n^{th}$ order has units:
A reaction proceeds in three stages. The first stage is slow and involves two molecules of reactants. The second and third stage are fast. The overall order of the reaction is:
The rate of the reaction, $A+B+C\rightarrow P$; is given by; $r=-\frac {d[A]}{dt}=K[A]^{1/2}[B]^{1/2}[C]^{1/4}$. The order of the reaction is:
The rate constant of nth order has units:
If the concentration is measured in mol $L^{-1}$ and time in minutes, the unit for the rate constant of a third order reaction is:
For which of the following reactions, the units of rate constant and rate of reaction are same ?
What is the order of reaction which has a rate expression as follows:
rate = k$[A]^{3/2}[B]^{-1}$
If a reaction involves gaseous reactants and products, the units of its rate are:
The rate of certain hypothetical reaction A + B + C $\rightarrow$ Products, is given by $\displaystyle r\, =\, - \frac{dA}{dt}\, = k[A]^{1/2}[B]^{1/3}[C]^{1/4}$ The order of a reaction is given by:
The second order rate constant is usually expressed as:
The rate of certain hypothetical reaction $A+B+C\rightarrow $ products is given by, $\displaystyle r=-\frac{\mathrm{d} [A]}{\mathrm{d} t}=K[A]^{1/2}:K[B]^{1/3}:K[C]^{1/4}$. The order of the reaction:
The rate constant of third order reaction is:
The rate constant of a reaction depends on:
The rate constant of a first-order reaction is $3 \times 10^{-6}$ per second and initial concentration is 0.10 M. Then the initial rate of reaction is:
What is the unit for the rate constant of a second order reaction?
Statement I : In a second order reaction doubling [A] quadruples the rate
Because
Statement II : The rate equation is $\displaystyle r={ k\left[ A \right] }^{ 2 }$ for such a reaction
For the reaction $A + B \rightarrow C$, determine the order of the reaction with respect to $B$ from the information given below.
$\displaystyle { \left[ A \right] } _{ \circ }$ | $\displaystyle { \left[ B \right] } _{ \circ }$ | Initial rate (M/s) |
---|---|---|
1.00 | 1.00 | 2.0 |
1.00 | 2.00 | 8.1 |
2.00 | 2.00 | 15.9 |
Statement 1: In a second-order reaction with respect to $A$, when you double [$A$], the rate is quadrupled.
Statement 2: The rate equation is $r = k[A]^2$ for such a reaction.
The unit for the rate constant is calculated from the rate law.
For the given rate law, determine the units of the rate constant for rate $= k[A]^{2} [B]$.
A graph of concentration versus time data for a second-order reaction gives a straight line in which of the following plots of the data?
The rate of the reaction, $C{ Cl } _{ 3 }CHO+NO\longrightarrow CH{ Cl } _{ 3 }+NO+CO$, is given by the equation, rate $=k\left[ C{ Cl } _{ 3 }CHO \right] \left[ NO \right] $. If concentration is expressed in ${mol}/{litre}$, the unit of $k$ is:
Units of rate constants for first and zero order reactions in terms of molarity $M$ unit are respectively:
Consider the reaction, $2A+B\longrightarrow $ Products. When the concentration of $B$ alone was doubled, the half-life did not change. When the concentration of $A$ alone was doubled, the rate increased by two times. The unit of the rate constant for this reaction is:
Consider following two reactions:
$A\longrightarrow $ Product, $-\dfrac { d\left[ A \right] }{ dt } ={ k } _{ 1 }{ \left[ A \right] }^{ 0 }$
$B\longrightarrow $ Product, $-\dfrac { d\left[ B \right] }{ dt } ={ k } _{ 2 }{ \left[ B \right] }^{ 1 }$
${ k } _{ 1 }$ and ${ k } _{ 2 }$ are expressed in terms of molarity $\left( mol\ { L }^{ -1 } \right) $ and time $\left( { s }\right) $ as:
Rate law expression of a reaction is:
Rate $=k{ \left[ A \right] }^{ { 2 }/{ 3 } }\left[ B \right] $
Which of the following are correct about the corresponding reaction?
Mechanism of a hypothetical reaction $X _2+Y _2\rightarrow 2XY$ is given below;
(i) $ X _2\rightarrow X+X$ (fast)
(ii) $X+Y _2\rightleftharpoons XY+Y$ (slow)
(iii) $ X+Y \rightarrow XY$ (fast)
The overall order of the reaction will be:
A reaction, which is second-order, has a rate constant of $0.002 L\, mol^{-1}\, s^{-1}$. If the initial conc. of the reactant is 0.2 M, how long will it take for the concentration to become 0.0400 M?
For the reaction $CO(g)+2{ H } { 2 }(g)\rightleftharpoons { CH } _{ 3 }OH(g)$. If active mass of $CO$ is kept constant and active mass of ${H} _{2}$ is tripled, the rate of forward reaction will become _____ of its initial value.
The reaction $2{NO} _{(g)}+{H} _{2(g)}\longrightarrow {N} _{2}{O} _{(g)}+{H} _{2}{O} _{(g)}$ follows the rate law $\cfrac { d{ P } _{ \left( { N } _{ 2 }O \right) } }{ dt } =k{ \left( { P } _{ NO } \right) }^{ 2 }{ p } _{ { H } _{ 2 } }$. If the reaction is initiated with ${P} _{NO}=1000mm$ $Hg$ and ${ p } _{ { H } _{ 2 } }=10mm$ $Hg$, then the reaction will follow:
The following data were obtained for the saponification of ethyl acetate using equal concentrations of ester and alkali. The reaction order is:
Time(min) | 0 | 4 | 10 | 20 |
---|---|---|---|---|
Vol. of acid(mL) | 8.04 | 5.30 | 3.50 | 2.22 |
For a reaction $r=K{[CH _3COCH _3]}^{3/2}$. The unit of rate of reaction and rate constant respectively is:
Which of the following corresponds to the units of rate constant for n$^{th}$ order reaction ?
The unit of rate of a first order reaction is:
For a particular $A+B \rightarrow C$ was studied at $25^{\circ}C$. The following results are obtained.
[A] | [B] | [C] |
---|---|---|
(mole/lit) | (moles/lit) | (mole lit $^{-1} sec^{-2}$) |
$9 \times 10^{-5}$ | $1.5 \times 10^{-2}$ | $0.06$ |
$9 \times 10^{-5}$ | $3 \times 10^{-3}$ | $0.012$ |
$3 \times 10^{-5}$ | $3 \times 10^{-3}$ | $0.004$ |
$6 \times 10^{-5}$ | x | $0.024$ |
Compound $A$ and $B$ react to form $C$ and $D$ in a reaction that was found to be second-order over all and second-order in $A$. The rate constant -at ${ 30 }^{ 0 }C$ is $0.622$ L ${ mol }^{ -1 }{ min }^{ -1 }$. What is the half-life of A when $4.10\times { 10 }^{ -2 }$ M of A is mixed with excess $B$?
The decomposition of dimethyl ether leads to the formation of $CH _4, H _2$ and CO and the reaction rate is given by $Rate=k[CH _3OCH _3]^{\frac {3}{2}}$
The rate of reaction is followed by increase in pressure in a closed vessel, so the rate can also be expressed in terms of the partial pressure of dimethyl ether, i.e., $Rate=k(P _{CH _3OCH _3})^{\frac {3}{2}}$
If the pressure is measured in bar and time in minutes, then the unit of rate constants is:
Taking the reaction, $A + 2B\rightarrow Products$, to be of the second order, which of the following may be the correct rate law expressions?
The rate constant of a second order reaction is $10^{-2} lit.mole ^{-1}.sec^{-1}$. The rate constant when expressed as $cc. \ molecule^{-1} .\ min^{-1}$ is:
In a certain reaction, 10% of the reactant decomposes in one hour, 20% in two hours, 30% in three hours and so on. Dimension of the velocity constant are:
When ethyl acetate was hydrolysed in presence of 0.1 N HCl, the rate constant was found to be $5.40\times 10^{-5}sec^{-1}$. But when 0.1 N $H _2SO _4$ was used for hydrolysis, the rate constant was found to be $6.25\times 10^{-5} sec^{-1}$. Thus, it may be concluded that:
The rate constant (K) for the reaction, $2A+B\rightarrow$ Product was found to be $2.5\times 10^{-5}$ litre $mol^{-1} sec^{-1}$ after 15 sec, $2.60\times 10^{-5} litre\ mol^{-1} sec^{-1}$ after 30 sec and $2.55\times 10^{-5} litre \ mol^{-1}sec^{-1}$ after 50 sec. The order of reaction is:
Assertion : In a second-order reaction with respect to A, when you double [A], the rate is quadrupled.
Reason : The rate equation is $\displaystyle r={ k\left[ A \right] }^{ 2 }$ for such a reaction.
For a gaseous reaction, $A\left( g \right) \longrightarrow $ Product, which one of the following is correct relation among $\dfrac { dP }{ dt } ,\dfrac { dn }{ dt }$ and $\dfrac { dc }{ dt } $?
($\dfrac { dP }{ dt } =$ Rate of reaction in $atm$ ${ sec }^{ -1 }$; $\dfrac { dc }{ dt } =$ Rate of reaction in molarity ${ sec }^{ -1 }$; $\dfrac { dn }{ dt } =$ Rate of reaction in $mol$ ${ sec }^{ -1 }$)
The rate constant for the reaction is $2 10^{-4} s^{-1}.$ The reaction is :
For a second-order reaction of the type rate=$k[A]^2$ the plot of $\dfrac{1}{[A] _1}$ versus t is linear with a: