Chemical Kinetics and Nuclear Chemistry

Assuming \(1 \,\mu \mathrm{g}\) of trace radioactive element X with a half life of 30 years is absorbed by a growing tree. The amount of X remaining in the tree after 100 years is ______ \(\times\, 10^{-1} \mu \mathrm{g}\).
[Given : ln 10 =...

For a first order reaction A \(\to\) B, the rate constant, k = 5.5 \(\times\) 10\(-\)14 s\(-\)1. The time required for 67% completion of reaction is x \(\times\) 10\(-\)1 times the half life of reaction. The value of x is _____________ (Nea...

A radioactive element has a half life of 200 days. The percentage of original activity remaining after 83 days is ___________. (Nearest integer)
(Given : antilog 0.125 = 1.333, antilog 0.693 = 4.93)

For the given first order reaction
\(\mathrm{A} \rightarrow \mathrm{B}\)
the half life of the reaction is \(0.3010 \mathrm{~min}\). The ratio of the initial concentration of reactant to the concentration of reactant at time $$2.0 \mathrm{~m...

For kinetic study of the reaction of iodide ion with \(\mathrm{H}_{2} \mathrm{O}_{2}\) at room temperature :
(A) Always use freshly prepared starch solution.
(B) Always keep the concentration of sodium thiosulphate solution less than that o...

For a reaction, given below is the graph of \(\ln k\) vs \({1 \over T}\). The activation energy for the reaction is equal to ____________ \(\mathrm{cal} \,\mathrm{mol}^{-1}\). (nearest integer)
(Given : $$\mathrm{R}=2 \,\mathrm{cal} \,\math...

The rate constant for a first order reaction is given by the following equation:
\(\ln k = 33.24 - {{2.0 \times {{10}^4}\,K} \over T}\)
The activation energy for the reaction is given by ____________ kJ mol\(-\)1. (In nearest integer) (Give...

It has been found that for a chemical reaction with rise in temperature by 9 K the rate constant gets doubled. Assuming a reaction to be occurring at 300 K, the value of activation energy is found to be ____________ kJ mol\(-\)1. [nearest i...

\(2 \mathrm{NO}+2 \mathrm{H}_{2} \rightarrow \mathrm{N}_{2}+2 \mathrm{H}_{2} \mathrm{O}\)
The above reaction has been studied at \(800^{\circ} \mathrm{C}\). The related data are given in the table below

.tg {border-collapse:collapse;borde...

\(\matrix{ {[A]} & \to & {[B]} \cr {{\mathop{\rm Reactant}\nolimits} } & {} & {{\mathop{\rm Product}\nolimits} } \cr }\)
If formation of compound \([\mathrm{B}]\) follows the first order of kinetics and after 70 minutes the c...

A flask is filled with equal moles of A and B. The half lives of A and B are 100 s and 50 s respectively and are independent of the initial concentration. The time required for the concentration of A to be four times that of B is __________...

Catalyst A reduces the activation energy for a reaction by 10 kJ mol\(-\)1 at 300 K. The ratio of rate constants, \({{{}^kT,\,Catalysed} \over {{}^kT,\,Uncatalysed}}\) is ex. The value of x is ___________. [nearest integer]
[Assume that the...

For a reaction \(\mathrm{A} \rightarrow 2 \mathrm{~B}+\mathrm{C}\) the half lives are \(100 \mathrm{~s}\) and \(50 \mathrm{~s}\) when the concentration of reactant \(\mathrm{A}\) is \(0.5\) and \(1.0 \mathrm{~mol} \mathrm{~L}^{-1}\) respect...

At \(30^{\circ} \mathrm{C}\), the half life for the decomposition of \(\mathrm{AB}_{2}\) is \(200 \mathrm{~s}\) and is independent of the initial concentration of \(\mathrm{AB}_{2}\). The time required for \(80 \%\) of the $$\mathrm{AB}_{2}...

For a given chemical reaction
\(\gamma\)1A + \(\gamma\)2B \(\to\) \(\gamma\)3C + \(\gamma\)4D
Concentration of C changes from 10 mmol dm\(-\)3 to 20 mmol dm\(-\)3 in 10 seconds. Rate of appearance of D is 1.5 times the rate of disappearance...

At 345 K, the half life for the decomposition of a sample of a gaseous compound initially at 55.5 kPa was 340 s. When the pressure was 27.8 kPa, the half life was found to be 170 s. The order of the reaction is ____________. [integer answer...

The half life for the decomposition of gaseous compound \(\mathrm{A}\) is \(240 \mathrm{~s}\) when the gaseous pressure was 500 Torr initially. When the pressure was 250 Torr, the half life was found to be \(4.0\) min. The order of the reac...

For the decomposition of azomethane.
CH3N2CH3(g) \(\to\) CH3CH3(g) + N2(g), a first order reaction, the variation in partial pressure with time at 600 K is given as

The half life of the reaction is __________ \(\times\) 10\(-\)5 s. [Neares...

The rate constants for decomposition of acetaldehyde have been measured over the temperature range 700 - 1000 K. The data has been analysed by plotting ln k vs \({{{{10}^3}} \over T}\) graph. The value of activation energy for the reaction ...

For a first order reaction, the time required for completion of 90% reaction is 'x' times the half life of the reaction. The value of 'x' is
(Given : ln 10 = 2.303 and log 2 = 0.3010)

According to the following figure, the magnitude of the enthalpy change of the reactionA + B \(\to\) M + N in kJ mol\(-\) is equal to ___________. (Integer answer)

For a first order reaction, the ratio of the time for 75% completion of a reaction to the time for 50% completion is ____________. (Integer answer)

For the reaction A \(\to\) B, the rate constant k(in s\(-\)1) is given by\({\log _{10}}k = 20.35 - {{(2.47 \times {{10}^3})} \over T}\)The energy of activation in kJ mol\(-\)1 is ____________. (Nearest integer) [Given : R = 8.314 J K\(-\)1 ...

For a reaction of order n, the unit of the rate constant is :

For the first order reaction A \(\to\) 2B, 1 mole of reactant A gives 0.2 moles of B after 100 minutes. The half life of the reaction is __________ min. (Round off to the nearest integer).[Use : ln 2 = 0.69, ln 10 = 2.3]Properties of logari...

The reaction that occurs in a breath analyser, a device used to determine the alcohol level in a person's blood stream is $$2{K_2}C{r_2}{O_7} + 8{H_2}S{O_4} + 3{C_2}{H_6}O \to 2C{r_2}{(S{O_4})_3} + 3{C_2}{H_4}{O_2} + 2{K_2}S{O_4} + 11{H_2}O...

The first order rate constant for the decomposition of CaCO3 at 700 K is 6.36 \(\times\) 10\(-\)3s\(-\)1 and activation energy is 209 kJ mol\(-\)1. Its rate constant (in s\(-\)1) at 600 K is x \(\times\) 10\(-\)6. The value of x is ________...

If the activation energy of a reaction is 80.9 kJ mol\(-\)1, the fraction of molecules at 700 K, having enough energy to react to form products is e\(-\)x. The value of x is __________. (Rounded off to the nearest integer) [Use R = 8.31 J K...

The following data was obtained for chemical reaction given below at 975 K.2NO(g) + 2H2(g) \(\to\) N2(g) + 2H2O(g)The order of the reaction with respect to NO is ___________. [Integer answer]

For the following graphs,Choose from the options given below, the correct one regarding order of reaction is :

For a chemical reaction A \(\to\) B, it was found that concentration of B is increased by 0.2 mol L\(-\) in 30 min. The average rate of the reaction is ____________ \(\times\) 10\(-\)1 mol L\(-\)1 h\(-\)1. (in nearest integer)

For the reaction, aA + bB \(\to\) cC + dD, the plot of log k vs \({1 \over T}\) is given below :The temperature at which the rate constant of the reaction is 10-4 s-1 is _________ K. (Rounded off to the nearest integer)[Given : The rate c...

The rate constant of a reaction increases by five times on increase in temperature from 27\(^\circ\)C to 52\(^\circ\)C. The value of activation energy in kJ mol\(-\)1 is _________. (Rounded off to the nearest integer)[R = 8.314 J K\(-\)1mol...

Gaseous cyclobutene isomerises to butadiene in a first order process which has a 'k' value of 3.3 \(\times\) 10-4 s-1 at 153°C. The time in minutes it takes for the isomerization to proceed 40% to completion at this temperature is ______....

Sucrose hydrolyses in acid solution into glucose and fructose following first order rate law with a half-life of 3.33 h at 25\(^\circ\)C. After 9 h, the fraction of sucrose remaining is f. The value of $${\log _{10}}\left( {{1 \over f}} \ri...

\({N_2}{O_{5(g)}} \to 2N{O_{2(g)}} + {1 \over 2}{O_{2(g)}}\)In the above first order reaction the initial concentration of N2O5 is 2.40 \(\times\) 10\(-\)2 mol L\(-\)1 at 318 K. The concentration of N2O5 after 1 hour was 1.60 \(\times\) 10$...

Isotope(s) of hydrogen which emits low energy \(\beta\)\(-\) particles with t1/2 value > 12 years is/are

The inactivation rate of a viral preparation is proportional to the amount of virus. In the first minute after preparation, 10% of the virus is inactivated. The rate constant for viral inactivation is ___________ \(\times\) 10\(-\)3 min$$-$...

\(PC{l_5}(g) \to PC{l_3}(g) + C{l_2}(g)\)In the above first order reaction the concentration of PCl5 reduces from initial concentration 50 mol L\(-\)1 to 10 mol L\(-\)1 in 120 minutes at 300 K. The rate constant for the reaction at 300 K is...

Which one of the following given graphs represents the variation of rate constant (k) with temperature (T) for an endothermic reaction?

2NO(g) + Cl2(g) \(\rightleftharpoons\) 2NOCl(s) This reaction was studied at \(-\)10\(^\circ\) and the following data was obtained


Run
\({[NO]_0}\)
\({[C{l_2}]_0}\)
\({r_0}\)




1
0.10
0.10
0.18

...

A reaction has a half life of 1 min. The time required for 99.9% completion of the reaction is _________ min. (Round off to the Nearest Integer). [Use : ln 2 = 0.69; ln 10 = 2.3]

For a certain first order reaction 32% of the reactant is left after 570s. The rate constant of this reaction is _________ \(\times\) 10\(-\)3 s\(-\)1. (Round off to the Nearest Integer). [Given : log102 = 0.301, ln10 = 2.303]

The reaction 2A + B2 \(\to\) 2AB is an elementary reaction.For a certain quantity of reactants, if the volume of the reaction vessel is reduced by a factor of 3, the rate of the reaction increases by a factor of ____________. (Round off t...

The decomposition of formic acid on gold surface follows first order kinetics. If the rate constant at 300 K is 1.0 \(\times\) 10\(-\)3 s\(-\)1 and the activation energy Ea = 11.488 kJ mol\(-\)1, the rate constant at 200 K is ____________ $...

A and B decompose via first order kinetics with half-lives 54.0 min and 18.0 min respectively. Starting from an equimolar non reactive mixture of A and B, the time taken for the concentration of A to become 16 times that of B is _________ m...

For the following reactions
\(A\buildrel {700K} \over \longrightarrow {\mathop{\rm Product}\nolimits}\)
\(A\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{catalyst}^{500K}} {\mathop{\rm Product}\nolimits}\)
it was found that Ea is dec...

A sample of milk splits after 60 min. at 300 K
and after 40 min. at 400 K when the population
of lactobacillus acidophilus in it doubles. The
activa tion energy (in kJ/ mol) for this process
is closest to__________.
(Given, R = 8.3 J mol–1 ...

The rate of a certain biochemical reaction at physiological temperature (T) occurs 106 times faster with
enzyme than without. The change in the activation energy upon adding enzyme is :

Consider the following plots of rate constant
versus \({1 \over T}\) for four different reactions. Which
of the following orders is correct for the
activation energies of these reactions?