Chemical Kinetics PYQs Set 8 (PDF)

Set 8 of 11 · Questions 211-240 of 311

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Chemical Kinetics · Set 8 (Q211-240)
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211. $For a first‐order reaction, the half‐life period is independent of$ (1) $first power of final concentration$ (2) $cube root of initial concentration$ (3) $initial concentration$ (4) $square root of final concentration$ 212. $For the reaction H_{2 (g)} + I_{2 (g)} ⇌ 2 HI_{(g)}, the rate of reaction is expressed as$ (1) $\frac{Δ [ H _{2} ]}{Δ t} = \frac{1Δ [ I _{2} ]}{2Δ t} = - \frac{Δ [ H I ]}{Δ t}$ (2) $- \frac{Δ [ I _{2} ]}{Δ t} = - \frac{Δ [ H _{2} ]}{Δ t} = \frac{1Δ [ H I ]}{2Δ t}$ (3) $\frac{Δ [ I _{2} ]}{Δ t} = \frac{Δ [ H _{2} ]}{Δ t} = \frac{Δ [ H I ]}{2Δ t}$ (4) $none of these$ 213. $Consider the given plots for a reaction obeying Arrhenius equation (0° C < T < 300° C) : (K and E_{a} are rate constant and activation energy, respectively. Choose the correct option$ (1) $I is right but II is wrong$ (2) $Both I and II are correct$ (3) $I is wrong but II is right$ (4) $Both I and II are wrong$ 214. $Consider the following plots of rate constant versus \frac{1}{T} for four different reactions. Which of the following orders is correct for the activation energies of these reactions?$ (1) $E_{c} > E_{a} > E_{d} > E_{b}$ (2) $E_{a} > E_{d} > E_{c} < E_{b}$ (3) $E_{c} > E_{b} > E_{a} > E_{d}$ (4) $E_{d} > E_{a} > E_{b} > E_{c}$ 215. $Consider the following reactions A \to P 1; B \to P 2; C \to P 3; D \to P 4 The order of the above reactions are a, b, c and d, respectively. The following graph is obtained when log[rate] vs . log [conc.] are plotted Among the following, the correct sequence for the order of the reactions is$ (1) $d > b > a > c$ (2) $d > a > b > c$ (3) $a > b > c > d$ (4) $c > a > b > d$ 216. $The correct reaction profile diagram for a positive catalyst reaction.$ (1) (2) (3) (4) 217. $When initial concentration of a reactant is doubled in a reaction, its half‐life period is not affected. The order of the reaction is$ (1) $second$ (2) $more than zero but less than first$ (3) $zero$ (4) $first.$ 218. $Which from following is the slope of the graph of rate versus concentration of the reactant for first order reaction?$ (1) $- k$ (2) $k$ (3) $\frac{k}{2.303}$ (4) $- k 2.303$ 219. $Mechanism of a hypothetical reaction X_{2} + Y_{2} \to 2 X Y, is given below: (i) X_{2} \to X + X (fast) (ii) X + Y_{2} \Leftrightarrow X Y + Y (slow) (iii) X + Y \to X Y (fast) The overall order of the reaction will be$ (1) $2$ (2) $0$ (3) $1.5$ (4) $1$ 220. $If 60% of a first order reaction was completed in 60 minutes, 50% ofthe same reaction would be completed in approximately (lo g 4 = 0.60, lo g 5 = 0.69)$ (1) $45 minutes$ (2) $60 minutes$ (3) $40 minutes$ (4) $50 minutes$ 221. $Consider the following reaction that goes from A to B in three steps as shown below: Choose the correct option Number of Intermediates Number of Activated Complexes Rate determining step 123 I 223 III 323 II 432 II$ (1) $(a)$ (2) $(b)$ (3) $(c)$ (4) $(d)$ 222. $Half‐life period of a first order reaction is 1386 seconds. The specific rate constant of the reaction is$ (1) $0. 5 \times 1 0^{- 2} s^{- 1}$ (2) $0. 5 \times 1 0^{- 3} s^{- 1}$ (3) $5. 0 \times 1 0^{- 2} s^{- 1}$ (4) $5. 0 \times 1 0^{- 3} s^{- 1} .$ 223. $The given graph is a representation of kinetics of a reaction. The y and x axes for zero and first order reactions, respectively are$ (1) $zero order (y= rate and x = c oncentration ), first order ( y= rate and x = t_{1/2})$ (2) $zero order (y= concentration and x= time ), first order y = t_{1/2} and x = c concentration )$ (3) $zero order (y= concentration and x= time ), first order ( y= rate constant and x = c oncentration)$ (4) $zero order ( y= rate and x= concentration), first order (y = t_{1/2} and x= concentration)$ 224. $For a zero order reaction A \to product, a plot of [A] (on y-axis) and time (on x -axis) gave a straight line with slope equal to - 3 \times 10^{- 3} M min^{- 1} and intercept equal to 2 \times 10^{- 2} M (on y-axis). What is the rate constant (in M min^{- 1}) of this reaction?$ (1) $3 \times 10^{- 3}$ (2) $5 \times 10^{- 5}$ (3) $3 \times 10^{- 4}$ (4) $5 \times 10^{- 4}$ 225. $Consider the following plots of log of rate constant k (log k) vs \frac{1}{T} for three different reactions. The correct order of activation energies of these reactions is:$ (1) $Ea_{2} > Ea_{1} > Ea_{3}$ (2) $Ea_{1} > Ea_{3} > Ea_{2}$ (3) $Ea_{3} > Ea_{2} > Ea_{1}$ (4) $Ea_{1} > Ea_{2} > Ea_{3}$ 226. $The following data was obtained for chemical reaction given below at 975 K. 2 N O_{(g)} + 2 H_{2 (g)} \to N_{2 (g)} + 2 H_{2} O_{(g)} The order of the reaction with respect to NO is ____. [Integer answer]$ 227. $For the adsorption of hydrogen on platinum, the activation energy is 30 kJ m o l^{- l} and for the adsorption of hydrogen on nickel, the activation energy is 41.4 kJ m o l^{- 1} . The logarithm of the ratio of the rates of chemisorption on equal areas of the metals at 300 K is________(Nearest integer) Given: In 10 = 2.3$ 228. $For a reaction, given below is the graph of In k vs \frac{1}{T} . The activation energy for the reaction is equal to________cal m o l^{- 1} . (Nearest integer). (Given : R = 2 cal K^{- 1} m o l^{- 1})$ 229. $An organic compound undergoes first order decomposition. If the time taken for the 60% decomposition is 540 s, then the time required for 90% decomposition will be is_______s. (Nearest integer). Given : ln 10 = 2,3; log 2 = 03$ 230. $For the reaction, aA + bB \to cC + dD the plot of log k vs \frac{1}{T} is given below: The temperature at which the rate constant of the reaction is 10^{- 4} s^{- 1} is ____ . [Rounded off to the nearest integer] [Given: The rate constant of the reaction is at 10^{- 5} s^{- 1} at 500K]$ 231. $K C 1 O_{3} + 6 F e S O_{4} + 3 H_{2} S O_{4} \to KC1 + 3 F e_{2} (S O_{4})_{3} + 3 H_{2} O The above reaction was studied at 300 K by monitoring the concentration of F e S O_{4} in which initial concentration was 10 M and after half an hour became 8. 8 M. The rate of production of F e_{2} (S O_{4})_{3} is_______x 1 0^{- 6} mol L^{- 1} s^{- l}$ 232. $The inactivation rate of a viral preparation is proportional to the amount of virus. In the first minute after preparation, 10% of the virus is inactivated. The rate constant for viral inactivation is ___\times 1 0^{- 3} mi n^{- 1} (Nearest integer) [Use: l n 10 = 2.303; l o g_{10} 3 = 0.477 property of logarithm : l o g x^{y} = y l o g x]$ 233. $If compound A reacts with B following first order kinetics with rate constant 2. 011 x 1 0^{- 3} s^{- 1} . The time taken by A (in seconds) to reduce from 7 g to 2 g will be________. (Nearest Integer) [log5 = 0.698, log7 = 0.845 log2 = 0.301]$ 234. $For the reaction A \to products. The concentration of A at 10 minutes is \times 10^{- 3} mol L^{- 1} (nearest integer). The reaction was started with 2.5 mol L^{- 1} of A.$ 235. $Given below are two statements : Statement I: The rate law for the reaction A + B \to C is rate (r) = k [A]^{2} [B] . When the concentration of both A and B is doubled, the reaction rate is increased " x " times. Statement II : The figure is showing "the variation in concentration against time plot" for a " y " order reaction. The Value of x + y is____$ 236. $Consider the following reaction A + B \to C The time taken for A to become 1/ 4^{th} of its initial concentration is twice the time taken to become 1/2 of the same. Also, when the change of concentration of B is plotted against time, the resulting graph gives a straight line with a negative slope and a positive intercept on the concentration axis. The overall order of the reaction is ______$ 237. $PCl_{5} (g) \to PCl_{3} (g) + Cl_{2} (g) In the above first order reaction the concentration of P C l_{5} reduces from initial concentration 50 m o l L^{- 1} to in 120 minutes at 300K. The rate constant for the reaction at 300K is x \times 1 0^{- 2} mi n^{- 1} . The value of x is ___ [Given log5=0.6989]$ 238. $For a chemical reaction A \to B, it was found thatconcentration of B is increased by 0.2mol L^{- 1} in 30min. The average rate of the reaction is \times 1 0^{- 1} m o l L^{- 1} h^{- 1} . (in nearest integer)$ 239. $The number of incorrect statement/s from the following is______________(A) The successive half lives of zero order reactions decreases with time.(B) A substance appearing as reactant in the chemical equation may not affect the rate of reaction(C) Order and molecularity of a chemical reaction can be a fractional number(D) The rate constant units of zero and second order reaction are and L respectively$ 240. $A(g) \to 2 B( g) + C(g) is a first order reaction. The initial pressure of the system was found to be 800 mm Hg which increased to 1600 mm Hg after 10 min . The total pressure of the system after 30 min will be mm Hg. (Nearest integer)$