Kinetic study of some first order reactions - class-X
Description: kinetic study of some first order reactions | |
Number of Questions: 55 | |
Created by: Shaka Gupte | |
Tags: chemistry chemical reactions and equations chemical kinetics |
The time required to complete $\dfrac{3}{4}th$ of first order reaction is $32 min.$ then find $t _{\frac{1}{2}} = ?$
The first order rate constant for dissociation of $N _2O _5$ is $6.2\times 10^{-4}s^{-1}$. The half-life period (in $s$) of this dissociation will be.
For a first order reaction with half-life of $150$ second , the time taken for the concentration of the reactant to fall from $M/10$ to $M/100$ will be approximately
How many minutes will it take to plate out $5.0g$ of $Cr$ form a $Cr _2(SO _4) _3$ solution using a current of $1.50A$?
Which of the following is first order ?
i) Decomposition of $NH _{4}NO _{3}$ in aqueous solution.
ii) Inversion of cane sugar in the presence of an acid
iii) Base hydrolysis of ethyl acetate.
iv) All radioactive decays.
The correct combination is:
The acid hydrolysis of the ester is:
(i) first order reaction
(ii) bimolecular reaction
(iii) unimolecular reaction
(iv) second order reaction
The hydrolysis of acetic anhydride$(CH _3CO) _2O+ H _2O\rightarrow2CH _3COOH$ is an example of :
The rate constant for the reaction $2{N} _{2}{O} _{5}\rightarrow 4{N}{O} _{2}+{O} _{2}$, is $3.0\times 10^{-5}\sec^{-1}$. lf the rate is $2.40\times 10^{-5}$ mol litre $sec^{-1}$ then, the concentration of ${N} _{2}{O} _{5} ($in mol $litre^{-1})$ is:
For which of the following reactions the molecularity and orders of the reaction are two and two respectively:
The rate constant, $\mathrm{k}$ for the reaction $\displaystyle \mathrm{N} _{2}\mathrm{O} _{5}(\mathrm{g})\rightarrow 2\mathrm{N}\mathrm{O} _{2}(\mathrm{g})+\frac{1}{2}\mathrm{O} _{2}(\mathrm{g})$ ls $2.3\times 10^{-2}\mathrm{s}^{-1}$. Which equation given below describes the change of $[\mathrm{N} _{2}\mathrm{O} _{5}]$ with time?
For the reaction; $2N _2O _5\rightarrow 4NO _2+O _2$, rate and rate constant are $1.02\times 10^{-4} M sec^{-1}$ and $3.4\times 10^{-5} sec^{-1}$ respectively, then concentration of $N _2O _5$, at that time will be:
For the first order reaction:-
$2N _2O _5(g)\rightarrow 4NO _2(g)+O _2(g)$
Among the following unimolecular reaction is
The reaction; $N _2O _5(g) \longrightarrow 2NO _2(g)+\frac {1}{2}O _2(g)$ is of first order for $N _2O _5$ with rate constant $6.2\times 10^{-4}s^{-1}$. What is the value of rate of reaction when $[N _2O _5]=1.25 \ mol L^{-1}$?
The concentration of acetate ions in $1 M$ acetic acid $(K _{a} = 2 \times 10^{-5})$ solution containing $0.1 M - HCl$ is
The hydrolysis of an ester was carried out with 0.1 M $H _2SO _4$ and 0.1 M HCl separately. Which of the following expressions between the rate consists is expected? The rate expression being rate = $k[H^{\oplus}][ester]$
$2N _2O _5\, \rightarrow\, 4NO _2\, +\, O _2$
If $\displaystyle -\, \frac{d[N _2O _5]}{dt}\, =\, k _1[N _2O _5]$
$\displaystyle \frac{d[NO _2]}{dt}\, =\, k _2[N _2O _5]$
$\displaystyle \frac{d[O _2]}{dt}\, =\, k _3[N _2O _5]$
What is the relation between $k _1, k _2\, and\, k _3$ ?
The inversion of cane sugar proceeds with the half-life of 500 min at pH 5 for any concentration of sugar. However, if pH = 6, the half life changes to 50 min. The rate law expression for the sugar inversion can be written as:
The hydrolysis of ethyl acetate in an acidic medium is a:
The reaction $2N _2O _5(g)\, \rightarrow\, 4NO _2(g)\, +\, O _2(g)$ is first order w.r.t. $N _2O _5$. Which of the following graphs would yield a straight line ?
When ethyl acetate was hydrolyzed in the presence of $0.1 M$ $HCl$, the constant was found to be $5.40\, \times\, 10^{-5}\, s^{-1}$. But when $0.1$ $M\, H _2SO _4$ was used for hydrolysis, the rate constant was found to be $6.20\, \times\,10^{-5}\, s^{-1}$. From these we can say that:
For the reaction $2N _2O _5\, \rightarrow\, 4NO _2\, +\, O _2$, if $\displaystyle -\, \frac{d[N _2O _5]}{dt}\, =\, k _1[N _2O _5]$, $\displaystyle \frac{d[NO _2]}{dt}\, =\, k _2[N _2O _5]$, $\displaystyle \frac{d[O _2]}{dt}\, =\, k _3[N _2O _5]$.
What is the relation between $k _1, k _2$ and $k _3$?
The rate law for the reaction : $:Ester+H^+\rightarrow Acid+Alcohol\,$ is
$V\,=\,k\;\left[ester \right]\;\left[H _3O^+ \right]^0$
What would be the new rate if
(a)$\;$conc. of ester is doubled
(b)$\;$conc. of $:H^{+}$ is doubled
In the presence of acid, the initial concentration of cane-sugar was reduced from 0.2 M to 0.1 in 5 hr and to 0.05 M in 10 hr. The reaction must be of :
The decomposition of $H _2O _2$ can be followed by titration with $KMnO _4$ and is found to be a first order reaction. The rate constant is $4.5\, \times\, 10^{-2}$. In an experiment, the initial titrate value was 25 mL. The titrate value will be 5 mL after a lapse of :
The half-life of decomposition of $N _2O _5$ is a first order reaction represented by:
$N _2O _5\rightarrow N _2O _4+1/2O _2$
The reaction $N _{2}O _{5}$ (in $CCl _{4}$) $\rightarrow 2NO _{2}+1/2O _{2}(g)$ is the first order in $N _{2}O _{5}$ with rate constant $6.2\times 10^{-4}S^{-1}$.
The half life of decomposition of $N _2O _5$ is a first order reaction represented by
$N _2O _5\, \rightarrow\, N _2O _4\, =\, 1/2O _2$
After 15 min the volume of $O _2$ produced is $9mL$ and at the end of the reaction $35 mL$. The rate constant is equal to :
The rate constant $k$, for the reaction
${N} _{2}{O} _{5}(g) \longrightarrow 2{NO} _{2}(g)+\cfrac{1}{2}{O} _{2}(g)$
is $1.3\times {10}^{-2}{s}^{-1}$. Which equation given below describes the change of $[{N} _{2}{O} _{5}]$ with time?
${[{N} _{2}{O} _{5}]} _{0}$ and ${[{N} _{2}{O} _{5}]} _{t}$ correspond to concentration of ${N} _{2}{O} _{5}$ initially and at time $t$.
Inversion of cane sugar in dilute acid is:
For the reaction, $2{N} _{2}{O} _{5}\longrightarrow 4{NO} _{2}+{O} _{2}$ the rate of reaction is:
The rate constant for the reaction,
$H _2O _2$ decomposes with first order kinetics in a 3 lit. container. If the pressure developed in 10 min. is 380 mm, the average rate at $27^oC$ is:
The rate constant of the reaction, $2{ H } _{ 2 }{ O } _{ 2 }\left( aq. \right) \rightarrow 2{ H } _{ 2 }O\left( l \right) +{ O } _{ 2 }\left( g \right) $, is $3\times { 10 }^{ -3 }{ min }^{ -1 }$.
At what concentration of ${ H } _{ 2 }{ O } _{ 2 }$, the rate of the reaction will be $2\times { 10 }^{ -4 }M{ s }^{ -1 }$?
Inversion of a sugar follows first order rate equation which can be followed by noting the change in rotation of the plane of polarisation of light in a polarimeter. If ${ r } _{ \infty },{ r } _{ t }$ and ${ r } _{ 0 }$ are the rotations at $t=\infty , t=t$ and $t=0$, then first order reaction can be written as:
The inversion of cane sugar into glucose and fructose is:
The rate constant for the hydrolysis reaction of an ester by dilute acid is $0.6931\times { 10 }^{ -3 }\ { s }^{ -1 }$. The time required to change the concentration of ester from $0.04$ $M$ to $0.01$ $M$ is:
Benzene diazonium chloride (A) decomposes into chloro-benzene (B) and ${{\text{N}} _{\text{2}}}\left( {\text{g}} \right)$ in first order reaction volume of ${{\text{N}} _2}$ collected after 5 min and at the complete decomposition of A are 10 ml and 50 ml respectively. The rate constant for the reaction is:
For the reaction of first order, $2{ N } _{ 2 }{ O } _{ 5 }\left( g \right) \rightleftharpoons 4N{ O } _{ 2 }\left( g \right) +{ O } _{ 2 }\left( g \right) $, which of the following statements are correct?
For the reaction, ${\text{2}}{{\text{N}} _{\text{2}}}{{\text{O}} _{\text{5}}} \to {\text{4N}}{{\text{O}} _{\text{2}}} + {{\text{O}} _{\text{2}}}$, the value of rate and rate constant are $1.02\times 10^{-4} M/s$ and $3.4 \times {10^{ - 3}}{\sec ^{ - 1}}$ respectively. The concentration of ${{\text{N}} _{\text{2}}}{{\text{O}} _{\text{5}}}$ at that time will be: (in terms of molarity)
The hydrolysis of ethyl acetate,
$CH _{3}COOC _{2}H _{5} + H _{2}O\xrightarrow {H^{+}} CH _{3}COOH + C _{2}H _{5}OH$ is a reaction of:
In the following reaction $2H _{2}O _{2}\rightarrow 2H _{2}O+O _{2}$ rate of formation of $O _{2}$ is 3.6 M $ min^{-1}.$ The rate of formation of $H _{2}O$ is:
At ${ 380 }^{ 0 }C$, the half life period for the first order decomposition of ${ H } _{ 2 }{ O } _{ 2 }$ is 360 minutes. The energy of activation of the reaction is 200 kJ ${ mol }^{ -1 }$. Calculate the time required for 75% decomposition at $450^{0}C$?
For the decomposition of $H _2O _2(aq.)$, it was found that $V _{O _2} (t=15 min.)$ was 100 mL (at 0$^oC$ and 1 atm) while $V _{O _2}$ (maximum) was 200 mL (at 0$^oC$ and 2 atm). If the same reaction had been followed by the titration method and if $V _{KMnO _4}^{cM} (t = 0)$ had been 40 mL, what would $V _{KMnO _4}^{cM}(t = 15 min)$ have been?
Which of the following are example of pseudo unimolecular reactions?
1. Inversion of cane sugar
2. Decomposition of ozone
3. Decomposition of $N _{2} O _{5}$
4. Acid catalysed by hydrolysis of ester
Which of the following statement is/are correct ?
The inversion of a sugar follows first-order rate equation which can be followed by noting the change in the rotation of the plane of polarization of light in the polarimeter. If $r _{\propto},\, r _{\zeta}$ and $r _0$ are the rotations at $t\, =\, \propto$, t = t, and t = 0, then the first order reaction can be written as:
The reaction, $Sucrose\xrightarrow [ ]{ { H }^{ + } } Glucose+Fructose$, takes place at certain temperature while the volume of solution is maintained at $1$ litre. At time zero the initial rotation of the mixture is ${ 34 }^{ o }C$.After $30$ minutes the total rotation of solution is ${ 19 }^{ o }C$ and after a very long time, the total rotation is ${ -11 }^{ o }C$. Find the time when solution was optically inactive?
Inversion of a sugar folllows first order rate equation which can be followed by nothing the change in rotation of the plane of polarization of light in the polarimeter. If $r _{\infty,}:r _t:and:r _0$ are the rotations at
$t\,=\,\infty,t\,=\,t:and:t\,=\,0,$ then, first order reaction can be written as:
In the following reaction $2H _2O _2\rightarrow2H _2O+O _2$ rate of formation of $O _2$ is 3.6 M min$^{-1}$.
(a) What is rate of formation of $H _2O\ ?$
Dinitropentaoxide decomposes as follows :
$N _2O _5:(g)\rightarrow2:NO _2(g)+\frac{1}{2}O _2:(g)$
Given that
$d:[NO _2]:/:dt=k _2[N _2O _5]$
$d:[O _2]:/:dt=k _3[N _2O _5]$
What is the relation between $k _1,:k _2:and:k _3$?
The following data were obtained in experiment on inversion of cane sugar.
Time (minutes) 0 60 120 180 360 $\infty $
Angle of rotation +13.1 +11.6 +10.2 +9.0 +5.87 -3.8
(degree)
Determine total time ?
Derive an expression for the Rate (k) of reaction :
$2N _{2}O _{5}(g)\rightarrow 4NO _{2}(g)+O _{2}(g)$
With the help of following mechanism:
$N _{2}O _{5}\overset{K _a}{\rightarrow}NO _{2}+NO _{3}$
$NO _{3}+NO _{2}\overset{K _{-a}}{\rightarrow}N _{2}O _{5}$
$NO _{2}+NO _{3}\overset{K _b}{\rightarrow}NO _{2}+O _{2}+NO$
$NO+NO _{3}\overset{K _c}{\rightarrow}2NO _{2}$
The rate constant for the reaction, ${ N } _{ 2 }{ O } _{ 5 }\left( g \right) \longrightarrow 2N{ O } _{ 2 }\left( g \right) +\dfrac { 1 }{ 2 } { O } _{ 2 }\left( g \right) $, is $2.3\times { 10 }^{ -2 }\ { sec }^{ -1 }$. Which equation given below describes the change of $\left[ { N } _{ 2 }{ O } _{ 5 } \right] $ with time, ${ \left[ { N } _{ 2 }{ O } _{ 5 } \right] } _{ 0 }$ and ${ \left[ { N } _{ 2 }{ O } _{ 5 } \right] } _{ t }$ corresponds to concentration of ${ N } _{ 2 }{ O } _{ 5 }$ initially and time $t$ respectively?