Home › Quizzes › Chemical Kinetics - class-XII

Chemical Kinetics - class-XII

Covers reaction rates, rate expressions, reaction order, rate constants, and graphical determination methods for chemical reactions

18 Questions Published
Play Quiz Practise this topic out loud

Questions

Question 1 Multiple Choice (Single Answer)

When a chemical reaction takes place, during the course of the reaction the rate of reaction?

  1. Keeps on increasing with time
  2. Remains constant with time
  3. Keeps on decreasing with time
  4. Shows irregular trend with time
Question 2 Multiple Choice (Single Answer)

In a reaction $2HI \rightarrow H _{2} + I _{2}$, the concentration of $HI$ decreases from $0.5\ mol\ L^{-1}$ to $0.4\ mol\ L^{-1}$ in $10$ minutes. What is the rate of reaction during this interval?

  1. $5\times 10^{-3} M\ min^{-1}$
  2. $2.5\times 10^{-3} M\ min^{-1}$
  3. $5\times 10^{-2} M\ min^{-1}$
  4. $2.5\times 10^{-2} M\ min^{-1}$
Question 3 Multiple Choice (Single Answer)

Which of the following statements is correct?

  1. The rate of a reaction decreases with passage of time as the concentration of reactants decreases.
  2. The rate of a reaction is same at any time during the reaction.
  3. The rate of a reaction is independent of temperature change.
  4. The rate of a reaction decreases with increase in concentration of reaction(s).
Question 4 Multiple Choice (Single Answer)

The rate constant of a zero order reaction is 0.2 mol $d{ m }^{ -3 }{ h }^{ -3 }$. If the concentration minutes is 0.05 mol $d{ m }^{ -3 }$. Then its initial concentration would be:

  1. $6.05 mol d{ m }^{ -3 }$
  2. $0.15 mol d{ m }^{ -3 }$
  3. $0.25 mol d{ m }^{ -3 }$
  4. none of the above
Question 5 Multiple Choice (Single Answer)

Consider the chemical reaction:
$N _2(g)+3H _2(g)\rightarrow 2NH _3(g)$


The rate of this reaction can be expressed; in terms of time and of concentration of $N _2(g), H _2(g)$ $NH _3(g)$. Identify the correct relationship amongst the rate expressions.

  1. Rate $=-\dfrac{d[N _2]}{dt}=-\dfrac{1}{3}\dfrac{d[H _2]}{dt}=+\dfrac{1}{2}\dfrac{d[NH _3]}{dt}$
  2. Rate $=-\dfrac{d[N _2]}{dt}=-\dfrac{3d[H _2]}{dt}=\dfrac{2d[NH _3]}{dt}$
  3. Rate $=-\dfrac{d[N _2]}{dt}=-\dfrac{1}{3}\dfrac{d[H _2]}{dt}=\dfrac{d[NH _3]}{dt}$
  4. Rate $=-\dfrac{d[N _2]}{dt}=\dfrac{d[H _2]}{dt}=\dfrac{d[NH _3]}{dt}$
Question 6 Multiple Choice (Single Answer)

Rate of formation of $SO _3$ in the following reaction $2SO _2+O _2\rightarrow 2SO _3$ is $100g$ $min^{-1}$. 


Then the rate of disappearance of $O _2$ is:

  1. $50g$ $min^{-1}$
  2. $40g$ $min^{-1}$
  3. $200g$ $min^{-1}$
  4. $20g$ $min^{-1}$
Question 7 Multiple Choice (Single Answer)

If concentration of reactants is increased by a factor x then the rate constant k becomes:

  1. $\ln{\frac{k}{x}}$
  2. $\frac{k}{x}$
  3. $k+x$
  4. $k$
Question 8 Multiple Choice (Single Answer)

An aqueous solution of $CH _3COOH$ has a pH = $3$ and acid dissociation constant of $CH _3COOH$ is $10^{-5}$. What will be the concentration of acid taken initially?

  1. $0.1$M
  2. $0.11$M
  3. $0.09$M
  4. $0.101$M
Question 9 Multiple Choice (Single Answer)

For the non-equilibrium process, $A + B \rightarrow Products$, the rate is first order with respect to $A$ and second-order with respect to $B$. If $1.0$ mole each of $A$ and $B$ are introduced into a 1-litre vessel and the initial rate was $1.0 \times 10^{-2}$ mol/litre-sec. The rate (in mol $litre^{-1} sec^{-1}$) when half of the reactants have been used:

  1. $1.2 \times 10^{-3}$
  2. $1.2 \times 10^{-2}$
  3. $2.5 \times 10^{-4}$
  4. none of these
Question 10 Multiple Choice (Single Answer)
 Time  0  5min  10min  15min
 [A]  20mol  18mol  16mol  16 mol

For the reaction $A\longrightarrow Products$; $\frac { -d[A] }{ dt } =k$ and at different time interval, IAI values are given. At $20$ minute, rate will be :

  1. $12 mol /min$
  2. $10 mol/min$
  3. $8 mol/min$
  4. $0.4 mol/min$
Question 11 Multiple Choice (Single Answer)

$H _2 + l _2 \rightarrow 2 Hl$ (An elementary reaction)
If the volume of the container containing the gaseous mixture is increased to two times, then final rate of the reaction

  1. Become four time
  2. Become $\dfrac{1}{4} th$ of the original rate
  3. Become $2$ times
  4. Become $\dfrac{1}{2}$ of the original rate
Question 12 Multiple Choice (Single Answer)

Assuming an element reaction $H _2O _2+ 3I^-+ 2H^+\to 2H _2O+ I _3^-.$ The effect on the rate of this reaction brought about by doubling the concentration of $I^-$ without changing the order?

  1. The rate would increases by a factor of $3$
  2. The rate would increase by a factor of $8$
  3. The rate would decrease by a factor of $1/3$
  4. The rate would increase by a factor of $9$
Question 13 Multiple Choice (Single Answer)

Instanteneous rate of reaction can be found be :

  1. slope of a rate of reaction vs time
  2. slope of a concentration vs time graph
  3. taking any two points on the graph
  4. both $B$ and $C$
Question 14 Multiple Choice (Single Answer)

For the reaction, $2{ N } _{ 2 }{ O } _{ 5 }\left( g \right) \longrightarrow 4N{ O } _{ 2 }\left( g \right) +{ O } _{ 2 }\left( g \right) $, if the concentration of $N{ O } _{ 2 }$ increases by $5.2\times { 10 }^{ -3 }M$ in $100$ sec, then the rate of reaction is:

  1. $1.3\times { 10 }^{ -5 }M{ s }^{ -1 }$
  2. $5\times { 10 }^{ -4 }M{ s }^{ -1 }$
  3. $7.6\times { 10 }^{ -4 }M{ s }^{ -1 }$
  4. $2\times { 10 }^{ -3 }M{ s }^{ -1 }$
  5. $2.5\times { 10 }^{ -5 }M{ s }^{ -1 }$
Question 15 Multiple Choice (Single Answer)

A reaction is represented as $2A + B \mapsto  2C + 3D$. The concentration of C at 10 s is 4 moles $l^{-1}$. The concentration of C at 20 seconds is 5.2 moles $l^{-1}$. The rate of reaction of B in the same time interval could be :

  1. $-0.12$ mole $l^{-1} S^{-1}$
  2. $-0.6$ mole $l^{-1} S^{-1}$
  3. $-0.06$ mole $l^{-1} S^{-1}$
  4. $-1.2$ mole $l^{-1} S^{-1}$
Question 16 Multiple Choice (Single Answer)

For $S{O _2}C{l _{2\left( g \right)}} \to S{O _{2\left( g \right)}} + C{l _{2\left( g \right)}},$ Pressures of $S{O _2}C{l _2}$ at $t = 0$ and $t = 20$ minutes respectively are $700mm$ and $350mm.$ When $\log \left( {{P _0}/p} \right)$ is plotted against time ($t$), slope equals to:

  1. $1.505 \times {10^{ - 2}}{s^{ - 1}}$
  2. $1.202 \times {10^{ - 3}}{\min ^{ - 1}}$
  3. $1.505 \times {10^{ - 2}}{\min ^{ - 1}}$
  4. $0.3465\ {\min ^{ - 1}}$
Question 17 Multiple Choice (Single Answer)

From the concentrations of R at different times given below. Determine  the average rate of the reaction range: R $\rightarrow$ P in given intervals of time.

t (s) 0 5 10 20 30
$10^{-3}, \times, [R] ,(mol, L^{-1})$ 160 80 40 10 2.5
  1. $3.5\times\,10^{2}$ to $0.42 \, \times\, 10^{2}$ $mol.L^{-1}\, s^{1}$
  2. $7\times\,10^{2}$ to $0.84 \, \times\, 10^{2}$ $mol.L^{-1}\, s^{1}$
  3. $8\times\,10^{3}$ to $0.37 \, \times\, 10^{3}$ $mol.L^{-1}\, s^{1}$
  4. $16\times\,10^{3}$ to $0.75 \, \times\, 10^{3}$ $mol.L^{-1}\, s^{1}$
← Back to Quizzes