Chemical Kinetics and Nuclear Chemistry

196 questions · Chemistry · JEE Main

Chemical Kinetics and Nuclear Chemistry

196 questions · Chemistry · JEE Main

For the reaction A $\to$ products. The concentration of A at 10 minutes is $\times 1 0^{- 3} mol L^{- 1}$ (nearest integer). The reaction was started with $2.5 mol L^{- 1}$ of A . Includes diagram2025 · 2 Apr · Shift 1 · Q21 · Numerical
Reactant A converts to product D through the given mechanism (with the net evolution of heat): A → B slow; ΔH = +ve B → C fast; ΔH = -ve C → D fast; ΔH = -ve Which of the following represents the above reaction mechanism?2025 · 2 Apr · Shift 2 · Q12 · MCQ
For the reaction $A \to B$ the following graph was obtained. The time required (in seconds) for the concentration of A to reduce to $2.5 g L^{- 1}$ (if the initial concentration of A was $50 g L^{- 1}$ … Includes diagram2025 · 2 Apr · Shift 2 · Q21 · Numerical
In a reaction $A + B \to C$ , initial concentrations of $A$ and $B$ are related as $[A]_{0} = 8 [B]_{0}$ . The half lives of $A$ and $B$ are 10 min and 40 min , respectively. If they start to disappear at the same time, both following first…2025 · 3 Apr · Shift 1 · Q19 · MCQ
Consider the following statements related to temperature dependence of rate constants. Identify the correct statements. A. The Arrhenius equation holds true only for an elementary homogenous reaction. B. The unit of $A$ is same as that of $k$ …2025 · 3 Apr · Shift 2 · Q11 · MCQ
For $A_{2} + B_{2} ⇌ 2 AB E_{a}$ for forward and backward reaction are 180 and $200 kJ mol^{- 1}$ respectively If catalyst lowers $E_{a}$ for both…2025 · 4 Apr · Shift 1 · Q1 · MCQ
Rate law for a reaction between $A$ and $B$ is given by $r = k [A]^{n} [B]^{m}$ If concentration of $A$ is doubled and concentration of $B$ is halved from their initial value, the ratio…2025 · 4 Apr · Shift 1 · Q4 · MCQ
Consider the following plots of $lo g$ of rate constant $k (lo g k)$ vs $\frac{1}{T}$ for three different reactions. The correct order of activation energies of these reactions is : Includes diagram2025 · 4 Apr · Shift 2 · Q2 · MCQ
Half life of zero order reaction $A \to$ product is 1 hour, when initial concentration of reactant is $2.0 mol L^{- 1}$ . The time required to decrease concentration of A from 0.50 to $0.25 mol L^{- 1}$ …2025 · 4 Apr · Shift 2 · Q9 · MCQ
Reaction $A (g) \to 2 B (g) + C (g)$ is a first order reaction. It was started with pure A Which of the following option is incorrect? Includes table2025 · 7 Apr · Shift 1 · Q18 · MCQ
A person's wound was exposed to some bacteria and then bacterial growth started to happen at the same place. The wound was later treated with some antibacterial medicine and the rate of bacterial decay(r) was found to be proportional with…2025 · 7 Apr · Shift 1 · Q2 · MCQ
A(g) → B(g) + C(g) is a first order reaction. The reaction was started with reactant A only. Which of the following expressions is correct for rate constant k? Includes table2025 · 7 Apr · Shift 2 · Q16 · MCQ
In a first order decomposition reaction, the time taken for the decomposition of reactant to one fourth and one eighth of its initial concentration are $t_{1}$ and $t_{2}$ (s), respectively. The ratio $t_{1} / t_{2}$ will be:2025 · 8 Apr · Shift 2 · Q4 · MCQ
$A \to B$ The molecule A changes into its isomeric form B by following a first order kinetics at a temperature of 1000 K . If the energy barrier with respect to reactant energy for such isomeric transformation is $191.48 kJ mol^{- 1}$ …2025 · 22 Jan · Shift 1 · Q24 · Numerical
Consider the given figure and choose the correct option : Includes diagram2025 · 22 Jan · Shift 2 · Q8 · MCQ
For the thermal decomposition of $N_{2} O_{5} (g)$ at constant volume, the following table can be formed, for the reaction mentioned below. $2 N_{2} O_{5} (g) \to 2 N_{2} O_{4} (g) + O_{2} (g)$ … Includes table2025 · 23 Jan · Shift 1 · Q21 · Numerical
Which of the following graphs most appropriately represents a zero order reaction?2025 · 23 Jan · Shift 2 · Q11 · MCQ
For a reaction, $N_{2} O_{5 (g)} \to 2 NO_{2 (g)} + \frac{1}{2} O_{2 (g)}$ in a constant volume container, no products were present initially. The final pressure of the…2025 · 24 Jan · Shift 1 · Q1 · MCQ
Given below are two statements : Statement (I) : is valid for first order reaction. Statement (II) : is valid for first order reaction. In the light of the above statements, choose the correct answer from the options given below : Includes diagram2025 · 24 Jan · Shift 2 · Q15 · MCQ
Consider a complex reaction taking place in three steps with rate constants $k_{1}, k_{2}$ and $k_{3}$ respectively. The overall rate constant $k$ is given by the expression $k = \frac{k _{1} k _{3}}{k _{2}}$ . If the…2025 · 24 Jan · Shift 2 · Q21 · Numerical
For a given reaction $R \to P, t_{1/2}$ is related to $[A]_{0}$ as given in table. Given: $lo g 2 = 0.30$ Which of the following is true? A. The order of the reaction is $1/2$ . B. If $[A]_{0}$ … Includes diagram2025 · 28 Jan · Shift 1 · Q5 · MCQ
Consider an elementary reaction $A (g) + B (g) \to C (g) + D (g)$ If the volume of reaction mixture is suddenly reduced to $\frac{1}{3}$ of its initial volume,…2025 · 28 Jan · Shift 2 · Q17 · MCQ
For bacterial growth in a cell culture, growth law is very similar to the law of radioactive decay. Which of the following graphs is most suitable to represent bacterial colony growth ? Where N - Number of Bacteria at any time, $N_{0}$ …2025 · 28 Jan · Shift 2 · Q20 · MCQ
The reaction $A_{2} + B_{2} \to 2 A B$ follows the mechanism: $A_{2} k_{- 1} ⇌ k_{1} A + A$ (fast) $A + B_{2} k_{2} A B + B$ (slow) $A + B \to A B$ (fast) The overall order of the reaction…2025 · 29 Jan · Shift 1 · Q8 · MCQ
Drug $X$ becomes ineffective after $50%$ decomposition. The original concentration of drug in a bottle was $16 mg / mL$ which becomes $4 mg / mL$ in 12 months. The expiry time of the drug in months is …2025 · 29 Jan · Shift 2 · Q19 · MCQ
The ratio of $\frac{^{14} C}{^{12} C}$ in a piece of wood is $\frac{1}{8}$ part that of atmosphere. If half life of $^{14} C$ is 5730 years, the age of wood sample is years.2024 · 1 Feb · Shift 1 · Q30 · Numerical
The following data were obtained during the first order thermal decomposition of a gas A at constant volume : $A (g) \to 2 B (g) + C (g)$ The rate constant of the reaction is … Includes table2024 · 1 Feb · Shift 2 · Q24 · Numerical
Consider the following transformation involving first order elementary reaction in each step at constant temperature as shown below. Some details of the above reactions are listed below. If the overall rate constant of the above… Includes table Includes diagram2024 · 4 Apr · Shift 1 · Q23 · Numerical
Consider the following reaction, the rate expression of which is given below $A + B \to C rate = k [A]^{1/2} [B]^{1/2}$ …2024 · 4 Apr · Shift 2 · Q26 · Numerical
During Kinetic study of reaction $2A + B \to C + D$ , the following results were obtained : Based on above data, overall order of the reaction is . Includes table2024 · 5 Apr · Shift 1 · Q30 · Numerical
Consider the following single step reaction in gas phase at constant temperature. $2 A_{(g)} + B_{(g)} \to C_{(g)}$ The initial rate of the reaction is recorded as $r_{1}$ …2024 · 5 Apr · Shift 2 · Q25 · Numerical
Time required for $99.9%$ completion of a first order reaction is times the time required for completion of $90%$ reaction.(nearest integer)2024 · 6 Apr · Shift 1 · Q22 · Numerical
Consider the two different first order reactions given below $A + B \to C (Reaction 1) P \to Q (Reaction 2)$ The…2024 · 6 Apr · Shift 2 · Q25 · Numerical
Consider the following reaction $A + B \to C$ The time taken for A to become $1/ 4^{th}$ of its initial concentration is twice the time taken to become $1/2$ of the same. Also, when the change…2024 · 8 Apr · Shift 1 · Q22 · Numerical
For a reaction $A K_{1} B K_{2} C$ If the rate of formation of B is set to be zero then the concentration of B is given by :2024 · 8 Apr · Shift 2 · Q11 · MCQ
Given below are two statements : Statement I : The rate law for the reaction $A + B \to C$ is rate $(r) = k [A]^{2} [B]$ . When the concentration of both $A$ and $B$ is doubled, the reaction rate is increased " $x$ "… Includes diagram2024 · 9 Apr · Shift 1 · Q26 · Numerical
Consider the following first order gas phase reaction at constant temperature $A (g) \to 2 B (g) + C (g)$ If the total pressure of the gases is found to be 200 torr after 23 $sec$ …2024 · 9 Apr · Shift 2 · Q26 · Numerical
Consider the following data for the given reaction $2 HI_{(g)} \to H_{2 (g)} + I_{2 (g)}$ The order of the reaction is . Includes diagram2024 · 27 Jan · Shift 1 · Q22 · Numerical
Time required for completion of $99.9%$ of a First order reaction is times of half life $(t_{1/2})$ of the reaction.2024 · 27 Jan · Shift 2 · Q24 · Numerical
For a reaction taking place in three steps at same temperature, overall rate constant $K = \frac{K _{1} K _{2}}{K _{3}}$ . If $Ea_{1}, Ea_{2}$ and $Ea_{3}$ are 40, 50 and $60 kJ / mol$ …2024 · 29 Jan · Shift 1 · Q26 · Numerical
The half-life of radioisotope bromine - 82 is 36 hours. The fraction which remains after one day is $\times 1 0^{- 2}$ . (Given antilog $0.2006 = 1.587$ )2024 · 29 Jan · Shift 2 · Q27 · Numerical
The rate of 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. Half life of the reaction is …2024 · 30 Jan · Shift 1 · Q28 · Numerical
$NO_{2}$ required for a reaction is produced by decomposition of $N_{2} O_{5}$ in $CCl_{4}$ as by equation $2 N_{2} O_{5 (g)} \to 4 NO_{2 (g)} + O_{2 (g)}$ …2024 · 30 Jan · Shift 2 · Q27 · Numerical
Integrated rate law equation for a first order gas phase reaction is given by (where $P_{i}$ is initial pressure and $P_{t}$ is total pressure at time $t$ )2024 · 31 Jan · Shift 1 · Q11 · MCQ
$r = k [A]$ for a reaction, $50%$ of $A$ is decomposed in 120 minutes. The time taken for $90%$ decomposition of $A$ is minutes.2024 · 31 Jan · Shift 2 · Q30 · Numerical
A and B are two substances undergoing radioactive decay in a container. The half life of A is 15 min and that of B is 5 min. If the initial concentration of B is 4 times that of A and they both start decaying at the same time, how much…2023 · 1 Feb · Shift 1 · Q15 · Numerical
$A$ $\to B$ The above reaction is of zero order. Half life of this reaction is $50 min$ . The time taken for the concentration of $A$ to reduce to one-fourth of its initial value is …2023 · 1 Feb · Shift 2 · Q23 · Numerical
Consider the following reaction that goes from A to B in three steps as shown below: Choose the correct option Includes diagram2023 · 6 Apr · Shift 2 · Q3 · MCQ
The number of given statement/s which is/are correct is . (A) The stronger the temperature dependence of the rate constant, the higher is the activation energy. (B) If a reaction has zero activation energy, its…2023 · 8 Apr · Shift 1 · Q15 · Numerical
The correct reaction profile diagram for a positive catalyst reaction.2023 · 8 Apr · Shift 2 · Q9 · MCQ
A molecule undergoes two independent first order reactions whose respective half lives are 12 min and 3 min. If both the reactions are occurring then the time taken for the 50% consumption of the reactant is min.…2023 · 10 Apr · Shift 1 · Q20 · Numerical
The number of incorrect statement/s from the following is A. The successive half lives of zero order reactions decreases with time. B. A substance appearing as reactant in the chemical equation may not affect the…2023 · 10 Apr · Shift 2 · Q16 · Numerical
$KClO_{3} + 6 FeSO_{4} + 3 H_{2} SO_{4} \to KCl + 3 Fe_{2} (SO_{4})_{3} + 3 H_{2} O$ The above reaction was studied at $300 K$ by…2023 · 11 Apr · Shift 1 · Q19 · Numerical
For a chemical reaction $A + B \to$ Product, the order is 1 with respect to $A$ and $B$ . What is the value of $x$ and $y$ ? Includes table2023 · 11 Apr · Shift 2 · Q13 · MCQ
The reaction $2 NO + Br_{2} \to 2 NOBr$ takes places through the mechanism given below: $NO + Br_{2} \Leftrightarrow NOBr_{2}$ (fast) $NOBr_{2} + NO \to 2 NOBr$ …2023 · 12 Apr · Shift 1 · Q20 · Numerical
$t_{87.5}$ is the time required for the reaction to undergo $87.5%$ completion and $t_{50}$ is the time required for the reaction to undergo $50%$ completion. The relation between $t_{87.5}$ and $t_{50}$ …2023 · 13 Apr · Shift 1 · Q16 · Numerical
A(g) $\to$ 2B(g) + C(g) is a first order reaction. The initial pressure of the system was found to be 800 mm Hg which increased to 1600 mm Hg after 10 min. The total pressure of the system after 30 min will be mm…2023 · 13 Apr · Shift 2 · Q13 · Numerical
For a reversible reaction $A ⇌ B$ , the $Δ H_{forward reaction} = 20 kJ mol^{- 1}$ . The activation energy of the uncatalysed forward reaction is $300 kJ mol^{- 1}$ …2023 · 15 Apr · Shift 1 · Q15 · Numerical
The number of correct statement/s from the following is A. Larger the activation energy, smaller is the value of the rate constant. B. The higher is the activation energy, higher is the value of the temperature…2023 · 24 Jan · Shift 1 · Q19 · Numerical
A student has studied the decomposition of a gas AB $_{3}$ at 25 $^{\circ}$ C. He obtained the following data. The order of the reaction is Includes table2023 · 24 Jan · Shift 2 · Q9 · MCQ
For the first order reaction A $\to$ B, the half life is 30 min. The time taken for 75% completion of the reaction is min. (Nearest integer) Given : log 2 = 0.3010 log 3 = 0.4771 log 5 = 0.69892023 · 25 Jan · Shift 1 · Q22 · Numerical
A first order reaction has the rate constant, $k = 4.6 \times 1 0^{- 3} s^{- 1}$ . The number of correct statement/s from the following is/are Given : $lo g 3 = 0.48$ A. Reaction completes in 1000 s. B.…2023 · 25 Jan · Shift 2 · Q16 · Numerical
For certain chemical reaction $X \to Y$ , the rate of formation of product is plotted against the time as shown in the figure. The number of $\underline{correct}$ statement/s from the following is . (A)… Includes diagram2023 · 29 Jan · Shift 1 · Q14 · Numerical
For conversion of compound A $\to$ B, the rate constant of the reaction was found to be $4.6 \times 1 0^{- 5} L mo l^{- 1} s^{- 1}$ . The order of the reaction is .2023 · 29 Jan · Shift 2 · Q23 · Numerical
If compound A reacts with B following first order kinetics with rate constant $2.011 \times 1 0^{- 3} s^{- 1}$ . The time taken by $A$ (in seconds) to reduce from $7 g$ to $2 g$ will be …2023 · 30 Jan · Shift 1 · Q15 · Numerical
An organic compound undergoes first-order decomposition. If the time taken for the $60%$ decomposition is $540 s$ , then the time required for $90%$ decomposition will be s. (Nearest integer). Given:…2023 · 30 Jan · Shift 2 · Q18 · Numerical
A $\to$ B The rate constants of the above reaction at 200 K and 300 K are 0.03 min $^{- 1}$ and 0.05 min $^{- 1}$ respectively. The activation energy for the reaction is J (Nearest integer) (Given : $ln10 = 2.3 R = 8.3 J K^{- 1} mo l^{- 1} lo g 5 = 0.70 lo g 3 = 0.48 lo g 2 = 0.30$ …2023 · 31 Jan · Shift 1 · Q23 · Numerical
The rate constant for a first order reaction is $20 min^{- 1}$ . The time required for the initial concentration of the reactant to reduce to its $\frac{1}{32}$ level is $\times 1 0^{- 2} min$ .…2023 · 31 Jan · Shift 2 · Q22 · Numerical
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 $\frac{10 ^{3}}{T}$ graph. The value of activation energy for the reaction… Includes diagram2022 · 24 Jun · Shift 1 · Q16 · Numerical
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)2022 · 24 Jun · Shift 2 · Q5 · MCQ
The half life for the decomposition of gaseous compound $A$ is $240 s$ 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 reaction…2022 · 25 Jul · Shift 1 · Q15 · Numerical
For the decomposition of azomethane. $C H_{3} N_{2} C H_{3}$ (g) $\to$ $C H_{3} C H_{3}$ (g) + $N_{2}$ (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 $\times$ … Includes diagram2022 · 25 Jul · Shift 2 · Q17 · Numerical
For a given chemical reaction $γ$ 1A + $γ$ 2B $\to γ$ 3C + $γ$ 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 of B…2022 · 25 Jun · Shift 1 · Q21 · Numerical
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 .…2022 · 25 Jun · Shift 2 · Q18 · Numerical
For a reaction $A \to 2 B + C$ the half lives are $100 s$ and $50 s$ when the concentration of reactant $A$ is $0.5$ and $1.0 mol L^{- 1}$ respectively.…2022 · 26 Jul · Shift 1 · Q22 · Numerical
At $3 0^{\circ} C$ , the half life for the decomposition of $AB_{2}$ is $200 s$ and is independent of the initial concentration of $AB_{2}$ . The time required for $80%$ of the $AB_{2}$ to…2022 · 26 Jul · Shift 2 · Q4 · MCQ
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 …2022 · 26 Jun · Shift 1 · Q15 · Numerical
Catalyst A reduces the activation energy for a reaction by 10 kJ mol $-$ 1 at 300 K. The ratio of rate constants, $\frac{^{k} T , C a t a l y se d}{^{k} T , U n c a t a l y se d}$ is ex. The value of x is . [nearest integer]…2022 · 26 Jun · Shift 2 · Q22 · Numerical
$2 NO + 2 H_{2} \to N_{2} + 2 H_{2} O$ The above reaction has been studied at $80 0^{\circ} C$ . The related data are given in the table below The order of the reaction with respect… Includes table2022 · 27 Jul · Shift 1 · Q15 · Numerical
$[A] Reactant o l imi t s \to [B] Product o l imi t s$ If formation of compound $[B]$ follows the first order of kinetics and after 70…2022 · 27 Jul · Shift 2 · Q18 · Numerical
The rate constant for a first order reaction is given by the following equation: $ln k = 33.24 - \frac{2.0 \times 10 ^{4} K}{T}$ The activation energy for the reaction is given by kJ mol $-$ 1. (In nearest…2022 · 27 Jun · Shift 1 · Q15 · Numerical
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…2022 · 27 Jun · Shift 2 · Q21 · Numerical
For kinetic study of the reaction of iodide ion with $H_{2} O_{2}$ at room temperature : (A) Always use freshly prepared starch solution. (B) Always keep the concentration of sodium thiosulphate solution less than that of…2022 · 28 Jul · Shift 1 · Q13 · MCQ
For the given first order reaction $A \to B$ the half life of the reaction is $0.3010 min$ . The ratio of the initial concentration of reactant to the concentration of reactant at time $2.0 min$ …2022 · 28 Jul · Shift 1 · Q18 · Numerical
For a reaction, given below is the graph of $ln k$ vs $\frac{1}{T}$ . The activation energy for the reaction is equal to $cal mol^{- 1}$ . (nearest integer) (Given : $R = 2 cal K^{- 1} mol^{- 1}$ … Includes diagram2022 · 28 Jul · Shift 2 · Q19 · Numerical
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 …2022 · 28 Jun · Shift 1 · Q21 · Numerical
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)2022 · 28 Jun · Shift 2 · Q16 · Numerical
The reaction between X and Y is first order with respect to X and zero order with respect to Y. Examine the data of table and calculate ratio of numerical values of M and L. (Nearest Integer) Includes table2022 · 29 Jul · Shift 1 · Q21 · Numerical
Assuming $1 μ g$ 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 $\times 1 0^{- 1} μ g$ .…2022 · 29 Jul · Shift 2 · Q19 · Numerical
The activation energy of one of the reactions in a biochemical process is 532611 J mol $-$ 1. When the temperature falls from 310 K to 300 K, the change in rate constant observed is k300 = x $\times$ 10 $-$ 3 k310. The value of x is …2022 · 29 Jun · Shift 1 · Q14 · Numerical
The equation k = (6.5 $\times$ 1012s $-$ 1)e $-$ 26000K/T is followed for the decomposition of compound A. The activation energy for the reaction is kJ mol $-$ 1. [nearest integer] (Given : R = 8.314 J K $-$ 1…2022 · 29 Jun · Shift 2 · Q18 · Numerical
For the reaction P $\to$ B, the values of frequency factor A and activation energy EA are 4 $\times$ 1013 s $-$ 1 and 8.3 kJ mol $-$ 1 respectively. If the reaction is of first order, the temperature at which the rate constant is 2…2022 · 30 Jun · Shift 1 · Q18 · Numerical
Which one of the following given graphs represents the variation of rate constant (k) with temperature (T) for an endothermic reaction?2021 · 1 Sep · Shift 2 · Q2 · MCQ
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 $\times$ …2021 · 16 Mar · Shift 1 · Q22 · Numerical
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 …2021 · 16 Mar · Shift 2 · Q19 · Numerical
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]2021 · 17 Mar · Shift 1 · Q18 · Numerical
The reaction 2 $A$ + $B_{2}$ $\to$ 2 $A B$ 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 …2021 · 17 Mar · Shift 2 · Q16 · Numerical
2NO(g) + Cl2(g) $⇌$ 2NOCl(s) This reaction was studied at $-$ 10 $^{\circ}$ and the following data was obtained $[N O]_{0}$ and $[C l_{2}]_{0}$ are the initial concentrations and r0 is the initial reaction rate. The overall… Includes table2021 · 18 Mar · Shift 1 · Q17 · Numerical
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]2021 · 18 Mar · Shift 2 · Q20 · Numerical
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…2021 · 20 Jul · Shift 1 · Q19 · Numerical
$P C l_{5} (g) \to P C l_{3} (g) + C l_{2} (g)$ In the above first order reaction the concentration of $P C l_{5}$ 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…2021 · 20 Jul · Shift 2 · Q22 · Numerical
$N_{2} O_{5 (g)} \to 2 N O_{2 (g)} + \frac{1}{2} O_{2 (g)}$ In the above first order reaction the initial concentration of $N_{2} O_{5}$ is 2.40 $\times$ 10 $-$ 2 mol L $-$ 1 at 318 K. The concentration of $N_{2} O_{5}$ after 1 hour was 1.60 $\times$ …2021 · 22 Jul · Shift 2 · Q22 · Numerical
Isotope(s) of hydrogen which emits low energy $β -$ particles with t1/2 value > 12 years is/are2021 · 22 Jul · Shift 2 · Q6 · MCQ
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 …2021 · 24 Feb · Shift 1 · Q22 · Numerical
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 $lo g_{10} (\frac{1}{f})$ …2021 · 24 Feb · Shift 2 · Q20 · Numerical
For the reaction, aA + bB $\to$ cC + dD, the plot of log k vs $\frac{1}{T}$ 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)… Includes diagram2021 · 25 Feb · Shift 1 · Q23 · Numerical
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 =…2021 · 25 Feb · Shift 2 · Q22 · Numerical
For the following graphs, Choose from the options given below, the correct one regarding order of reaction is : Includes diagram2021 · 25 Jul · Shift 1 · Q7 · MCQ
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)2021 · 25 Jul · Shift 2 · Q20 · Numerical
The following data was obtained for chemical reaction given below at 975 K. 2 $N O$ (g) + 2 $H_{2}$ (g) $\to$ $N_{2}$ (g) + 2 $H_{2} O$ (g) The order of the reaction with respect to $N O$ is . [Integer answer] Includes diagram2021 · 26 Aug · Shift 1 · Q19 · Numerical
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)…2021 · 26 Feb · Shift 2 · Q18 · Numerical
The reaction that occurs in a breath analyser, a device used to determine the alcohol level in a person's blood stream is $2 K_{2} C r_{2} O_{7} + 8 H_{2} S O_{4} + 3 C_{2} H_{6} O \to 2 C r_{2} (S O_{4})_{3} + 3 C_{2} H_{4} O_{2} + 2 K_{2} S O_{4} + 11 H_{2} O$ …2021 · 27 Aug · Shift 1 · Q14 · Numerical
The first order rate constant for the decomposition of $C a C O_{3}$ 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 …2021 · 27 Aug · Shift 2 · Q13 · Numerical
For a reaction of order n, the unit of the rate constant is :2021 · 27 Jul · Shift 1 · Q3 · MCQ
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]…2021 · 27 Jul · Shift 2 · Q21 · Numerical
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)2021 · 31 Aug · Shift 1 · Q17 · Numerical
According to the following figure, the magnitude of the enthalpy change of the reaction A + B $\to$ M + N in kJ mol $-$ is equal to . (Integer answer) Includes diagram2021 · 31 Aug · Shift 1 · Q19 · Numerical
For the reaction A $\to$ B, the rate constant k(in s $-$ 1) is given by $lo g_{10} k = 20.35 - \frac{( 2.47 \times 10 ^{3} )}{T}$ The energy of activation in kJ mol $-$ 1 is . (Nearest integer) [Given : R =…2021 · 31 Aug · Shift 2 · Q18 · Numerical
The results given in the below table were obtained during kinetic studies of the following reaction 2A + B $\to$ C + D X and Y in the given table are respectively : Includes diagram2020 · 2 Sep · Shift 2 · Q13 · MCQ
It is true that :2020 · 3 Sep · Shift 1 · Q5 · MCQ
For the reaction 2A + 3B + $\frac{3}{2}$ C $\to$ 3P, which statement is correct ?2020 · 3 Sep · Shift 2 · Q3 · MCQ
If 75% of a first order reaction was completed in 90 minutes, 60% of the same reaction would be completed in approximately (in minutes) . (Take : log 2 = 0.30; log 2.5 = 0.40)2020 · 4 Sep · Shift 1 · Q9 · Numerical
The number of molecules with energy greater than the threshold energy for a reaction increases five fold by a rise of temperature from 27oC to 42oC. Its energy of activation in J/mol is . (Take ln 5 = 1.6094; R =…2020 · 4 Sep · Shift 2 · Q9 · Numerical
A flask contains a mixture of compounds A and B. Both compounds decompose by first-order kinetics. The half-lives for A and B are 300 s and 180 s, respectively. If the concentrations of A and B are equal initially, the time required for…2020 · 5 Sep · Shift 1 · Q2 · MCQ
The rate constant (k) of a reaction is measured at differenct temperatures (T), and the data are plotted in the given figure. The activation energy of the reaction in kJ mol–1 is : (R is gas constant) Includes diagram2020 · 5 Sep · Shift 2 · Q14 · MCQ
Consider the following reactions A $\to$ $P_{1}$ ; B $\to$ $P_{2}$ ; C $\to$ $P_{3}$ ; D $\to$ $P_{4}$ , The order of the above reactions are a, b, c, and d, respectively. The following graph is obtained when log[rate] vs. log[conc.] are plotted… Includes diagram2020 · 6 Sep · Shift 1 · Q8 · MCQ
The rate of a reaction decreased by 3.555 times when the temperature was changed from 40oC to 30oC. The activation energy (in kJ mol–1) of the reaction is . Take; R = 8.314 J mol–1 K–1 ln 3.555 = 1.2682020 · 6 Sep · Shift 2 · Q7 · Numerical
During the nuclear explosion, one of the products is 90Sr with half life of 6.93 years. If 1 $μ$ g of 90Sr was absorbed in the bones of newly born baby in placed of Ca, how much time, in years, is required to reduce much time, in year,…2020 · 7 Jan · Shift 1 · Q3 · Numerical
For the reaction 2 $H_{2}$ (g) + 2 $N O$ (g) $\to$ $N_{2}$ (g) + 2 $H_{2} O$ (g) the observed rate expression is, rate = Kf[ $N O$ ]2[ $H_{2}$ ]. The rate expression for the reverse reaction is :2020 · 7 Jan · Shift 2 · Q15 · MCQ
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 :2020 · 8 Jan · Shift 1 · Q14 · MCQ
Consider the following plots of rate constant versus $\frac{1}{T}$ for four different reactions. Which of the following orders is correct for the activation energies of these reactions? Includes diagram2020 · 8 Jan · Shift 2 · Q4 · MCQ
For the following reactions $A 700 K Product o l imi t s A c a t a l y s t ⟶ 500 K Product o l imi t s$ it was found that Ea is decreased by 30 kJ/mol in the…2020 · 9 Jan · Shift 1 · Q7 · MCQ
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 .…2020 · 9 Jan · Shift 2 · Q8 · Numerical
For the reaction 2A + B $\to$ C, the values of initial rate at diffrent reactant concentrations are given in the table below. The rate law for the reaction is : Includes table2019 · 8 Apr · Shift 1 · Q20 · MCQ
For a reaction scheme $A k_{1} B k_{2} C$ , if the rate of formation of B is set to be zero then the concentration of B is given by :2019 · 8 Apr · Shift 2 · Q11 · MCQ
The given plots represent the variation of the concentration of a reactant R with time for two different reactions (i) and (ii). The respective orders of the reactions are : Includes diagram2019 · 9 Apr · Shift 1 · Q9 · MCQ
Consider the given plot of enthalpy of the following reaction between A and B. A+ B $\to$ C + D Identify the incorrect statement. Includes diagram2019 · 9 Apr · Shift 2 · Q7 · MCQ
The following results were obtained during kinetic studies of the reaction ; 2A + B $\to$ Products The time (in minutes) required to consume half of A is : Includes table2019 · 9 Jan · Shift 1 · Q13 · MCQ
For the reaction, 2A + B $\to$ products, when the concentrations of A and B both were doubled, the rate of the reaction increased from 0.3 mol L $-$ 1s $-$ 1 to 2.4 mol L $-$ 1s $-$ 1. When the concentration of A alone is doubled, the rate…2019 · 9 Jan · Shift 2 · Q18 · MCQ
A bacterial infection in an internal wound grows as N'(t) = N0 exp(t), where the time t is in hours. A does of antibiotic, taken orally, needs 1 hour to reach the wound. Once it reaches there, the bacterial population goes down as $\frac{d N}{d t} = - 5 N^{2}$ …2019 · 10 Apr · Shift 1 · Q14 · MCQ
For the reaction of $H_{2}$ with $I_{2}$ , the rate constant is 2.5 × 10–4 dm3 mol–1s–1 at 327°C and 1.0 dm3 mol–1 at 527°C. The activation energy for the reaction, in kJ mole–1 is : (R = 8.314 JK–1 mol–1 )2019 · 10 Apr · Shift 2 · Q15 · MCQ
Consider the given plots for a reaction obeying Arrhenius equation (0oC < T < 300oC) : (K and Ea are rate constant and activation energy, respectively) Choose the correct option : Includes diagram2019 · 10 Jan · Shift 1 · Q8 · MCQ
For an elementary chemical reaction, the expression for $\frac{d [ A ]}{d t}$ is Includes diagram2019 · 10 Jan · Shift 2 · Q6 · MCQ
If a reaction follows the Arrhenius equation, the plot ln k vs $\frac{1}{( R T )}$ gives straight line with a gradient ( $-$ y) unit. The energy required to active the reactant is :2019 · 11 Jan · Shift 1 · Q9 · MCQ
The reaction 2X $\to$ B is a zeroth order reaction. If the initial concentration of X is 0.2 M, the half-life is 6 h. When the initial concentration of X is 0.5 M, the time required to reach its final concentration of 0.2 M will be:2019 · 11 Jan · Shift 2 · Q13 · MCQ
In the following reaction; xA $\to$ yB $lo g_{10} [- \frac{d [ A ]}{d t}] = lo g_{10} [\frac{d [ B ]}{d t}] + 0.3010$ 'A' and 'B' respectively can be :2019 · 12 Apr · Shift 1 · Q10 · MCQ
$N O_{2}$ required for a reaction is produced by the decomposition of $N_{2} O_{5}$ in $C C l_{4}$ as per the equation, 2 $N_{2} O_{5}$ (g) $\to$ 4 $N O_{2}$ (g) + $O_{2}$ (g). The initial concentration of $N_{2} O_{5}$ is 3.00 mol L–1 and it is 2.75 mol L–1 after 30…2019 · 12 Apr · Shift 2 · Q11 · MCQ
Decomposition of X exhibits a rate constant of 0.05 $μ$ g/year. How many year are required for the decomposition of 5 $μ$ g of X into 2.5 $μ$ g?2019 · 12 Jan · Shift 1 · Q8 · MCQ
For a reaction consider the plot of $ℓ$ n k versus 1/T given in the figure. If the rate constant of this reaction at 400 K is 10–5 s–1, then the rate constant at 500 K is – Includes diagram2019 · 12 Jan · Shift 2 · Q10 · MCQ
$N_{2} O_{5}$ decomposes to $N O_{2}$ and $O_{2}$ and follows first order kinetics. After 50 minutes, the pressure inside the vessel increases from 50 mmHg to 87.5 mmHg. The pressure of the gaseous mixture after 100 minute at constant temperature…2018 · 15 Apr · Shift 1 · Q22 · MCQ
For a first order reaction, A $\to$ P, t1/2 (half-life) is 10 days The time required for $\frac{1}{4}$ th conversion of A (in days) is : (ln 2 = 0.693, ln 3 = 1.1)2018 · 15 Apr · Shift 2 · Q14 · MCQ
If 50% of a reaction occurs in 100 second and 75% of the reaction occurs in 200 secod, the order of this reaction is :2018 · 16 Apr · Shift 1 · Q8 · MCQ
At 518oC the rate of decomposition of a sample of gaseous acetaldehyde initially at a pressure of 363 Torr, was 1.00 Torr s–1 when 5% had reacted and 0.5 Torr s–1 when 33% had reacted. The order of the reaction is2018 · Shift 0 · Q16 · MCQ
The rate of a reaction A doubles on increasing the temperature from 300 to 310 K. By how much, the temperature of reaction B should be Increased from 300 K so that rate doubles if activation energy of the reaction B is twice to that of…2017 · 8 Apr · Shift 1 · Q19 · MCQ
The rate of a reaction quadruples when the temperature changes from 300 to 310 K. The activation energy of this reaction is : (Assume activation energy and preexponential factor are independent of temperature; ln 2 = 0.693; R = 8.314 J…2017 · 9 Apr · Shift 1 · Q17 · MCQ
Two reactions $R_{1}$ and $R_{2}$ have identical pre-exponential factors. Activation energy of $R_{1}$ exceeds that of $R_{2}$ by 10 kJ mol–1. If $k_{1}$ and $k_{2}$ are rate constants for reactions $R_{1}$ and $R_{2}$ respectively at 300 K, then…2017 · Shift 0 · Q14 · MCQ
The reaction of ozone with oxygen atoms in the presence of chlorine atoms can occur by a two step process shown below : $O_{3}$ (g) + Cl $^{∙}$ (g) $\to$ $O_{2}$ (g) + ClO $^{∙}$ (g) . . . . . .(i) ki = 5.2 × 109 L mol−1 s−1 ClO $^{∙}$ …2016 · 9 Apr · Shift 1 · Q15 · MCQ
The rate law for the reaction below is given by the expression k [A] [B] A + B $\to$ Product If the concentration of B is increased from 0.1 to 0.3 mole, keeping the value of A at 0.1 mole, the rate constant will be :2016 · 10 Apr · Shift 1 · Q14 · MCQ
Decomposition of $H_{2} O_{2}$ follows a first order reaction. In fifty minutes the concentration of $H_{2} O_{2}$ decreases from 0.5 to 0.125 M in one such decomposition. When the concentration of $H_{2} O_{2}$ reaches 0.05 M, the rate of formation of $O_{2}$ …2016 · Shift 0 · Q1 · MCQ
Higher order (>3) reactions are rare due to2015 · Shift 0 · Q20 · MCQ
For the non – stoichiometre reaction 2A + B $\to$ C + D, the following kinetic data were obtained in three separate experiments, all at 298 K. The rate law for the formation of C is: Includes table2014 · Shift 0 · Q22 · MCQ
The rate of a reaction doubles when its temperature changes from 300K to 310K. Activation energy of such a reaction will be:(R = 8.314 JK–1 mol–1 and log 2 = 0.301)2013 · Shift 0 · Q14 · MCQ
For a first order reaction, (A) $\to$ 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 :2012 · Shift 0 · Q18 · MCQ
The rate of a chemical reaction doubles for every 10oC rise of temperature. If the temperature is raised by 50oC , the rate of the reaction increases by about :2011 · Shift 0 · Q22 · MCQ
The time for half life period of a certain reaction A $\to$ products is 1 hour. When the initial concentration of the reactant ‘A’, is 2.0 mol L–1, how much time does it take for its concentration to come from 0.50 to 0.25 mol L–1 if it is…2010 · Shift 0 · Q18 · MCQ
Consider the reaction : $C l_{2}$ (aq) + $H_{2} S$ (aq) → $S$ (s) + 2 $H^{+}$ (aq) + 2 $C l^{-}$ (aq) The rate equation for this reaction is rate = k [ $C l_{2}$ ] [ $H_{2} S$ ] Which of these mechanisms is/are consistent with this rate equation? (A) $C l_{2}$ +…2010 · Shift 0 · Q19 · MCQ
The half life period of a first order chemical reaction is 6.93 minutes. The time required for the completion of 99% of the chemical reaction will be (log 2=0.301) :2009 · Shift 0 · Q19 · MCQ
For a reaction $\frac{1}{2} A \to 2 B$ rate of disappearance of ‘A’ is related to the rate of appearance of ‘B’ by the expression2008 · Shift 0 · Q22 · MCQ
Which of the following nuclear reactions will generate an isotope?2007 · Shift 0 · Q23 · MCQ
A radioactive element gets spilled over the floor of a room. Its half-life period is 30 days. If the initial activity is ten times the permissible value, after how many days will it be safe to enter the room?2007 · Shift 0 · Q24 · MCQ
Consider the reaction, 2A + B $\to$ products. When 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 rate constant for this…2007 · Shift 0 · Q25 · MCQ
The energies of activation for forward and reverse reactions for $A_{2}$ + $B_{2}$ $⇋$ 2 $A B$ are 180 kJ mol−1 and 200 kJ mol−1 respectively. The presence of catalyst lowers the activation energy of both (forward and reverse)…2007 · Shift 0 · Q26 · MCQ
Rate of a reaction can be expressed by Arrhenius equation as: $k = A e^{- E / R T}$ In this equation, E represents2006 · Shift 0 · Q28 · MCQ
A reaction was found to be second order with respect to the concentration of carbon monoxide. If the concentration of carbon monoxide is doubled, with everything else kept the same, the rate of reaction will2006 · Shift 0 · Q34 · MCQ
In the transformation of $_{92}^{238} U$ to $_{92}^{234} U$ , if one emission is an α-particle, what should be the other emission(s)?2006 · Shift 0 · Q35 · MCQ
The following mechanism has been proposed for the reaction of $N O$ with $B r_{2}$ to form $N O B r$ : $N O$ (g) + $B r_{2}$ (g) $⇋$ $N O B r_{2}$ (g) $N O B r_{2}$ (g) + $N O$ (g) $\to$ 2 $N O B r$ (g) If the second step is the rate determining…2006 · Shift 0 · Q36 · MCQ
A schematic plot of $l n K_{e q}$ versus inverse of temperature for a reaction is shown below The reaction must be Includes diagram2005 · Shift 0 · Q27 · MCQ
Hydrogen bomb is based on the principle of2005 · Shift 0 · Q37 · MCQ
A reaction involving two different reactants can never be2005 · Shift 0 · Q38 · MCQ
The photon of hard gamma radiation knocks a proton out of $_{12}^{24} M g$ nucleus to form2005 · Shift 0 · Q39 · MCQ
t1/4 can be taken as the time taken for the concentration of a reactant to drop to $\frac{3}{4}$ of its initial value. If the rate constant for a first order reaction is K, the t1/4 can be written as2005 · Shift 0 · Q40 · MCQ
Consider the following nuclear reactions $_{92}^{238} M \to_{Y}^{X} N + 2_{2}^{4} H e_{Y}^{X} N \to_{B}^{A} L + 2 β^{+}$ The number of neutrons in the element L is2004 · Shift 0 · Q29 · MCQ
In a first order reaction, the concentration of the reactant decreases from 0.8 M to 0.4 M in 15 minutes. The time taken for the concentration to change from 0.1 M to 0.025 M is2004 · Shift 0 · Q41 · MCQ
The rate equation for the reaction 2A + B $\to$ C is found to be: rate k[A][B]. The correct statement in relation to this reaction is that the2004 · Shift 0 · Q42 · MCQ
The half – life of a radioisotope is four hours. If the initial mass of the isotope was 200 g, the mass remaining after 24 hours undecayed is2004 · Shift 0 · Q43 · MCQ
The radionucleide $_{90}^{234} T h$ undergoes two successive $β$ -decays followed by one $α$ -decay. The atomic number and the mass number respectively of the resulting radionucleide are2003 · Shift 0 · Q38 · MCQ
The half-life of a radioactive isotope is three hours. If the initial mass of the isotope were 256 g, the mass of it remaining undecayed after 18 hours would be2003 · Shift 0 · Q39 · MCQ
In respect of the equation k = Ae-Ea/RT in chemical kinetics, which one of the following statements is correct?2003 · Shift 0 · Q40 · MCQ
The rate law for a reaction between the substances A and B is given by Rate = k[A]n [B]m On doubling the concentration of A and halving the concentration of B, the ratio of the new rate to the earlier rate of the reaction will be as2003 · Shift 0 · Q41 · MCQ
For the reaction system: 2 $N O$ (g) + $O_{2}$ (g) $\to$ 2 $N O_{2}$ (g) volume is suddenly reduce to half its value by increasing the pressure on it. If the reaction is of first order with respect to $O_{2}$ and second order with respect to $N O$ , the…2003 · Shift 0 · Q42 · MCQ
Units of rate constant of first and zero order reactions in terms of molarity M unit are respectively2002 · Shift 0 · Q37 · MCQ
For the reaction A + 2B $\to$ C, rate is given by R = [A] [B]2 then the order of the reaction is2002 · Shift 0 · Q38 · MCQ
The differential rate law for the reaction $H_{2}$ + $I_{2}$ $\to$ 2 $H I$ is2002 · Shift 0 · Q39 · MCQ
If half-life of a substance is 5 yrs, then the total amount of substance left after 15 years, when initial amount is 64 grams is2002 · Shift 0 · Q40 · MCQ
$β$ - particle is emitted in radioactivity by2002 · Shift 0 · Q41 · MCQ
The integrated rate equation is Rt = log C0 - log Ct . The straight line graph is obtained by plotting2002 · Shift 0 · Q42 · MCQ