**MHT-CET 2008** * *

*1 *.
After how many seconds will the concentration of the reactant in a
first order reaction be halved if the rate constant is 1.155 x 10^-3
s^-1

- (A) 600
- (B) 100
- (C) 60
- (D) 10

**MHT-CET 2009**

** ***2*. Which is a correct integrated rate equation?

- (A) k = -2.303/t log a/(a - x)
- (B) k = -2.303/t log (a - x)/a
- (C) -d (a - x) = k dt
- (D) All are integrated rate equations

*3.* For which order reaction, the unit of rate constant is time^-1 ?

- (A) Zero order
- (B) First order
- (C) Second order
- (D)Third order

**MHT-CET 2010**

*4.* The units of rate constant for first order reaction are

- (A) mol L
^{-1}s^{-1} - (B) s
^{-1} - (C) L mol
^{-1}s^{-1} - (D) L² mol
^{-2}s^{-1}

*5.*The first order integrated rate equation is

- (A) k = x/t
- (B) k = -2.303/t log a/(a-x)
- (C) k = 1/t ln a/(a-x)
- (D) k = 1/t x/a(a-x)

**MHT-CET 2011**

*6.*In a multistep reaction, the overall rate of reaction is equal to the

- (A) rate of slowest step
- (B) rate of fastest step
- (C) average rate of various steps
- (D) the rate of last step

*7*. What is the activation energy for a reaction if its rate doubles when the temperature is raised from 20°C to 35°C ? (R = 8.314 J mo1

^{-1}K

^{-1}

- (A) 342 kJ mo1
^{-1} - (B) 269 kJ mol
^{-1} - (C) 34.7 kJ mol
^{-1} - (D) 15.1 kJ mol
^{-1}

**MHT-CET 2014**

*8*. Rate law for the reaction A + B → product is rate = k [A]

^{2}[B]. What is the rate constant if the rate of reaction at a given temperature is 0.22 Ms

^{-1}. when [A] = 1M and [B] = 0.25 M?

- (A) 3.52 M
^{-2}s^{-1} - (B) 0.88 M
^{-2}s^{-1} - (C) 1.136 M
^{-2}s^{-1} - (D) 0.05 M
^{-2}s^{-1}

**MHT-CET 2015**

*9*. For the reaction O

_{3}(g) + O(g) → 2O

_{2}(g) if the rate law expression is, rate = k [O

_{3}] [O] the molecularity and order of the reaction are respectively

- (A) 2 and 2
- (B) 2 and 1.33
- (C) 2 and 1
- (D) 1 and 2

*10*. The relationship between rate constant and half-life period of zero order reaction is given by

- (A) t
_{1/2}= [A]_{0}2kt - (B) t
_{1/2}= 0.693/k - (C) t
_{1/2 =}[A]_{0 }/2k - (D) t
_{1/2}= 2[A]_{0}/k

*11.*Half-life period of a first order reaction. A → product is 6.93 hour. What is the value of rate constant?

- (A) 1.596 h
^{-1} - (B) 0.1 h
^{-1} - (C) 4.802 h
^{-1} - (D) 10 h
^{-1}

^{MHT-CET 2016 }

*12*. The reaction takes place in two steps as

i) NO

^{2}C^{(g)}→ NO^{2}^{(g)}+ Cl^{(g)}ii) NO^{2}Cl^{(g)}+ Cl^{(g)}→ NO^{2}^{(g)}+ C1^{2}^{(g)}Identify the reaction intermediate.- (A)NO
^{2}Cl^{(g)} - (B) NO
^{2}^{(g)} - (C) Cl
^{2}^{(g)} - (D) Cl
^{(g)}

*13*. The rate constant and half-life of a first order reaction are related to each other as

- (A) t
_{1/2}= 0.693/k - (B) t
_{1/2}= 0.693 k - (C) k = 0.693 t
_{1/2} - (D) kt
_{1/2}= 1/0.693

*14*. Average rate of reaction 2 SO

_{2}

_{(g)}+ O

_{2}

_{(g)}→ 2SO

_{3}

_{(g)}is written as

- (A) △[SO
_{2}]/△t - (B) -△[O
_{2}]/△t - (C) 1/2△[SO
_{2}]/△t - (D) △[SO
_{3}]/△t

**MHT-CET 2017**

*15*. Which among the following reactions is an example of pseudo first order reaction?

- (A) Inversion of cane sugar
- (B) Decomposition of H
_{2}O_{2} - (C) Conversion of cyclopropane to propene
- (D) Decomposition of N
_{2}O_{5}

*16*. Which among the following equations represents Arrhenius equation?

- (A) k = A.e
^{Ea/RT} - (B) k = A.e
^{RT/Ea} - (C) k = A/e
^{Ea/RT} - (D) k = A/e
^{RT/Ea}

*17.*The rate constant for a first order reaction 7.0 x 10^-4 s^-1. If initial concentration of reactant is 0.080, what is the half-life of reaction?

- (A) 990 s
- (B) 79.2 s
- (C) 12375 s
- (D) 10.10 x 10^-4

**MHT-CET 2018**

*18.*A certain reaction occurs in two steps as

i) 2SO2(g) + 2NO2(g) → 2SO3(g) + 2NO(g) ii) 2NO(g) + O2(g) → 2NO2(g)

in the reaction,

- (A) NO2(g) is intermediate
- (B) NO(g) is intermediate
- (C) NO(g) is catalyst
- (D) O2(g) is intermediate

*19.*Slope of the straight line obtained by plotting log

_{10}k against 1/T represents what term?

- (A) -E
_{a} - (B) -2.303 E
_{a}/R - (C) -E
_{a}/2.303 R - (D) -E
_{a}/R

**MHT-CET 2019**

*20.*For the elementary reaction 2SO

_{2}

_{(g)}+ O

_{2}

_{(g)}→ 2SO

_{3}

_{(g)}, identify the correct among the following relations:

- (A) +d[SO
_{3}_{(g)}]/dt = -2d[O_{2}_{(g)}]/dt - (B) +d[SO
_{2}_{(g)}]/dt = -d[O_{2}_{(g)}]/dt - (C) +1/2d[SO
_{3}_{(g)}]/dt = d[SO_{2}_{(g)}]/dt - (D) -d[SO
_{2}_{(g)}]/dt = -d[O_{2}_{(g)}]/dt

*21.*Which among the following reaction is an example of a zero order reaction?

- (A) 2NH
_{3}→ N_{2}_{(g)}+ 3H_{2} - (B) C
_{12}H_{22}O_{11}_{(aq.)}+ H_{2}O_{(l)}→ C_{6}H_{12}O_{6}_{(aq.)}+ C_{6}H_{12}O_{6}_{(aq.)} - (C) H
_{2}_{(g)}+ I_{2}_{(g)}→ 2HI_{(g)} - (D) 2H
_{2}O_{2}_{(l)}→ 2H_{2}_{(l)}+ O_{ 2}_{(g)}

*22.*The activation energy of a reaction is zero. Its rate constant at 280 K is 1.6 x 10^-6 s^-1, the rate constant at 300 K is

- (A) 1.6 x 10^-6 s^-1
- (B) 1.6 x 10^-5 s^-1
- (C) 3.2 x 10^-6 s^-1
- (D) Zero

*23*. For a chemical reaction rate law is. rate = k [A]² [B]. If [A] is doubled at constant [B], the rate of reaction

- (A) increases by a factor of 4
- (B) increases by a factor of 3
- (C) increases by a factor of 8
- (D) increases by a factor of 2

*24*. For the elementary reaction, 3 H

_{2}

_{(g)}+ N

_{2}

_{(g)}→ 2NH

_{3}

_{(g)}, identify the correct relation among the following relations.

- (A) -3/2d[H2(g)]/dt = d[NH3(g)]/dt
- (B) d[NH3(g)]/dt = -1/3 d[H2(g)]/dt
- (C) -2/3d[H2(g)]/dt = d[NH3(g)]/dt
- (D) -[H2(g)]/dt = d[NH3(g)]/dt

*25.*The integrated rate equation for first order reaction, A → Product, is

_{10}[A]

_{0/[A]t}

_{t}/[A]

_{0}

_{10}[A]

_{0}/[A]

_{t}

_{t}/[A]

_{0}

_{ }

*26*. Order of which among the following reactions is NOT one?

- (A) 2H2O2(l) → 2H2O(l) + O2(g)
- (B) Cyclopropane → CH3 -- CH == CH2(g)
- (C) 2N2O5(g) → 2NO2(g) + O2(g)
- (D) CHCl3(g) + Cl2(g) → CCl4(g) + HCl(g)

*27.*Consider the reaction 2A + B → product. When conc. of 'B' alone was doubled, the half-life, is not change. When conc. of 'A' alone was doubled, the rate increases by two times, order of of reaction is

- (A) 2
- (B) 1.5
- (C) 1
- (D) 0

*28*. Consider the reaction 2A + 2B → C + 2D, if concentration of A is doubled at constant [B], rate increases by a factor 4. If concentration B is doubled at constant [A] the rate is doubled. Rate law of the reaction is

- (A) rate = k[A]2 [B]
- (B) rate = k[A] [B]2
- (C) rate = k[A]2 [B]2
- (D) rate = k[A] [B]

*29*. If the half-life period of a first order reaction is 200 minutes, the rate constant will be

- (A) 9.605 x 10^-2 min^-1
- (B) 3.465 x 10^-3 min^-1
- (C) 1.374 x 10^-3 min^-1
- (D) 288.6 min^-1

*30*. If the rate of reaction is expressed as, -1/3d[A]/dt = -1/2d[B]/dt = d[C]/dt, the reaction is

- (A) 3A + 2B → C
- (B) 2B → 3A + C
- (C) 2B + C → 3A
- (D) 3A → 2B + C

*31*. A → B is first order reaction with rate equal to 6.6 x 10^-5 M s^-1. When [A] is 0.6 M, rate constant of the reaction is

- (A) 9 x 10^-5 s^-1
- (B) 9 x 10^-4 s^-1
- (C) 1.1 x 10^-4 s^-1
- (D) 1.1 x 10^-5 s^-1

**MHT-CET 2020**

*32*. Which of the following is a character of catalyst?

- (A) It increases the rates of both forward and backward reactions equally in reversible reaction
- (B) It increases the activation energy of reactants
- (C) It affects the energies of reactants and products of the reaction
- (D) It changes the position of equilibrium

*33*. In the reaction. N2 is + 3H2 → 2NH3, the rate of disappearance of H2 is 0.02 M/s. The rate of appearance of NH3 is

- (A) 0.0133 M/s
- (B) 0.004 M/s
- (C) 0.032 M/s
- (D) 0.023

*34*. Which among the following is correct when energy of activation, Ea of the catalyzed reaction decreases at constant temperature and for same concentration?

- (A) e
^{-Ea/RT}decreases - (B) -Ea/RT decreases
- (C) K decreases
- (D) Ea/RT decreaces

*35*. Half-life of first order reaction is 20 minutes. What is the time taken to reduce the initial concentration of the reactant to 1/10 th ?

- (A) 66.56 min
- (B) 6.6 min
- (C) 150 min
- (D) 79.68 min

*36*. The rate law for the reaction 2NO(g) + O2(g) → 2NO2(g) is rate = k[NO]²[O2], then which

among the following is correct?

- (A) The reaction is first order in O2, first order in NO and second order overall
- (B) The reaction is second order in NO, zero order in O2 and second order overall
- (C) The reaction is second order in NO, first order in O2 and third order overall
- (D) The reaction is zero order overall

*37.*In a first order reaction 87.5% of reactant is converted into product in 15 minutes. The rate constant for the reaction is given by

- (A) 5/0.693 min^-1
- (B) 0.693/15 min^-1
- (C) 0.693 x 5 min^-1
- (D) 0.693/5 min^-1

*38.*The half-life of a first order reaction is 6.0 hour. How long will it take for the concentration of reactant to decrease from 0.4 M to 0.12 M?

- (A) 10.42 h
- (B) 9.51 h
- (C) 30.36 h
- (D) 4.25 h

*39*. For the first order reaction A → B, the rate constant is 0.25 s^-1, if the concentration of A is reduced to half, the value of rate constant will be

- (A) 0.25 s^-1
- (B) 0.30 s^-1
- (C) 2.25 s^-1
- (D) 0.075 s^-1

*40.*For the reaction 4NH3 + 5O2 → 4NO + 6H2O, the rate of disappearance of NH3 is 3.6 x 10^-3M/s. What is the rate of formation of water?

- (A) 6.0 x 10^-4 M/s
- (B) 5.4 x 10^-3 M/s
- (C) 3.6 x 10^-3 M/s
- (D) 4.0 x 10^4 M/s

*41.*The rate law for the reaction A + B + C → Product is expressed as Rate = k[A]² [B]1 [C]0. What is the overall order of the reaction?

- (A) 3
- (B) 1
- (C) 2
- (D) 0

*42*. The reaction N205 → 2NO2 + 1/2O2 is first order in N205 having rate constant 6.2 x 10^-4 s^-1. What is the value of rate of reaction when concentration of N2O5 is 1.25 mol L^-1?

- (A) 7.75 x 10^-4 mol L^-1 s^-1
- (B) 8.15 x 10^-4 mol L^-1 s^-1
- (C) 4.96 x 10^-4 mol L^-1 s^-1
- (D) 2.01 x 10^-4 mol L^-1 s^-1

*43*. The rate constant for first order reaction is 0.02232 min^-1. Calculate the time required for 75% completion of the reaction.

- (A) 62.12 min
- (B) 38.31 min
- (C) 48.12 min
- (D) 12.77 min

*44*. Which among the following is an example of zero order reaction?

- (A) Hydrolysis of CH3COOCH3
- (B) inversion of C12H22O11
- (C) Decomposition of N2O in presence of catalyst
- (D) Decomposition of N2O5

*45*. What is the unit of rate constant for the zero order reaction?

- (A) t^-1
- (B) mol dm³ t^-1
- (C) mol dm^-3 t^-1
- (D) mol dm^-3 t

*46*. For first order reaction the slope of the graph of log[A]t Vs. time is equal to

- (A) k
- (B) -k
- (C) -k/2.303
- (D) k/2.303

*47.*What is the order of reaction for decomposition of gaseous acetaldehyde?

- (A) 0
- (B) 2
- (C) 1.5
- (D) 1

*48*. If concentration of reactant 'A' is increased by 10 times, the rate of reaction becomes 100 times. What is the order of reaction if rate law is, rate = k[A]x

- (A) 2
- (B) 1
- (C) 3
- (D) 4

*49.*A first order reaction has rate constant 1 x 10^-2 s^-1. What time will it take for 20 g of reactant to reduce to 5 g?

- (A) 138.6 s
- (B) 238.6 s
- (C) 693.0 s
- (D) 346.5 s

*50*. What is the value of rate constant of first order reaction, if it takes 15 minutes for consumption of 20% of reactants?

- (A) 1.07 x 10^-2 min^-1
- (B) 1.48 x 10^-2 min^-1
- (C) 1.84 x 10^-2 min^-1
- (D) 1.38 x 10^-2 min^-1

*51.*A first order reaction has a rate constant 0.00813 min^-1, how long will it take for 60% completion?

- (A)112.7 min
- (B) 56.35 min
- (C) 62.77 min
- (D) 98.7 min

*52*. Half-life of first order reaction X → Y + Z is 3 minutes. What is the time required to reduce the concentration of 'X' by 90 % of it's initial concentration?

- (A) 9.969 minutes
- (B) 4.12 minutes
- (C) 9.105 minutes
- (D) 12.05 minutes

*53*. A first order reaction is 25% completed in 40 minutes. What is the rate constant k for reaction?

- (A) 2.303/40 x log1/4
- (B) (2.303 x log 1.33)/40
- (C) (2.303 x log 4)/120
- (D) 2.303 x log 4/3

*54*. For first order reaction the concentration of reactant decreases form 0.2 to 0.1 M in 100 minutes What is the rate constant of the reaction?

- (A) 144.3 min^-1
- (B) 6.93 min^-1
- (C) 69.3 min^-1
- (D) 6.93 x 10^-3 min^-1

*55*. A first order reaction is 75% completed in 60 minutes, the time required for it's 50% completion is

- (A) 30 min
- (B) 60 min
- (C) 120 min
- (D) 40 min

*56*. What is the molecularity and order of the following reaction if rate law is, rate = k[O3][O] respectively?

O3(g) + O(g) → 2O2(g)

- (A) 3 and 1
- (B) 3 and 2
- (C) 4 and 2
- (D) 2 and 2

*57*. For a first order reaction, A → B, if [A] = 1 M and rate is 4 x 10^-2 M s^-1. What is the rate constant of the reaction?

- (A) 4 x 10^-2 s^-1
- (B) 0.4 x 10^-2 s^-1
- (C) 2 x 10^-2 s^-1
- (D) 2.5 x 10^-5 s^-1

*58*. For the reaction, 2NOBr(g) → 2NO(g) + Br2(g), rate law is r = k [NOBr]².

If rate constant is 1.62 Ms^-1 and concentration of NOBr is 2.00 x 10^-3M, what is the rate of reaction?

- (A) 2.46 x 10^-6 Ms^-1
- (B) 5.24 x 10^-6 Ms^-1
- (C) 6.48 x 10^-6 Ms^-1
- (D) 4.05 x 10^-5 Ms^-1

*59*. In the reaction 2SO2 + O2 → 2SO3 the rate of appearance of SO3 is 4 x 10^-4 M/s, the rate of disappearance of O2 is

- (A) 1.0 x 10^-4 M/s
- (B) 4.0 x 10-4 M/s
- (C) 2.0 x 10^-4
- (D) 6.0 x 10^-4 M/s

*60*. Which among the following is an example of pseudo first order reaction?

- (A) 2N2O5(g) → 4NO2(g) + O2(g)
- (B) CH2 --CH2-- CH2 → CH3 -- CH= CH2
- (C) H2O2(l) → 2H2)(l) + O2(g)
- (D) CH3COOCH3(aq.) + H2O → CH3COOH(aq.) + CH3OH(aq.)

*61*. Which is the average rate of reaction when the change in concentration of product is 0.05 M in 20 seconds?

- (A) 4.0 m/s
- (B) 0.05 M/s
- (C) 0.0025 M/s
- (D) 1.0 M/s

*62.*In the reaction A + B2 → AB + B, the rate of reaction is direct, proportional to the cocentration of A and independent on the concentration of B2. What is the rate law expression?

- (A) rate = k[A]
- (B) rate = k[B2]
- (C) rate = k[A][B2]
- (D) rate = K[A]
^{2}[B2]

*63.*The rate for the reaction is r1 = k[A][B]. If the concentration of A is doubled and that of B is halved, the new rate is r2 then what is the ratio of r2/r1?

- (A) 2^( a – b)
- (B) a - b
- (C) a + b
- (D) 1/2^(a+b)

*64*. The reaction 2NO2Cl(g) → 2NO2(g) + Cl2(g) takes place in two steps its

(i) NO2Cl(g) → 2NO2(g) + Cl2(g)

(ii) NO2Cl(g) + Cl(g) → NO2(g) + Cl2(g)

Identify the reaction intermediate.

- (A) NO2(g)
- (B) NO2Cl(g)
- (C) Cl(g)
- (D) C12(g)

65.1n
the reaction 2SO2(g) + O2(g) → 2SO3(g), the rate of disappearance of
SO2 is 1.28 x 10^-5 M/s. What is the rate of appearance of SO3?

- (A) 2.56 x 10^-5 M/s
- (B) 1.25 x 10^-5 M/s
- (C) 0.64 x 10^-5 M/s
- (D) 0.32 x 10^-5 M/s

*66*. A first order reaction takes 40 minutes for 30% decomposition. What is the half-life of reaction?

- (A) 59.5 min
- (B) 77.8 min
- (C) 67.8 min
- (D) 82.2 min

*67*. A certain zero order reaction is 50% completed in 10 minutes. What percentage does the reaction completes after 15 minutes?

- (A) 65%
- (B) 25%
- (C) 75%
- (D) 60%

*68*. In a reaction N2(g) + 3H2(g) → 2NH3(g), if the rate of disappearance of N2(g) is 2.6 x 10^-4 M/s, the rate of disappearance of H2(g) in M/s is

- (A) 8.6 x 10^-4 M/s
- (B) 5.2 x 10^-4 M/s
- (C) 2.6 x 10^-4 M/s
- (D) 7.8 x 10-4 M/s

*69*. Which is the unit of rate constant for the first order reaction if time is expressed in seconds?

- (A) mol^-1 dm³ s^-1
- (B) s^-1
- (C) mol dm^-3 s^-1
- (D) mol dm^-3 s

*70*. Reaction given below follows first order kinetics: 2 N2O2 → 4NO2 + O2

Calculate rate constant of reaction if concentration of N2O2 is 0.05 M and rate of reaction is

1.5 x 10^-6 mol L^-1 s^-1

- (A) 2.5 x 10^-5 s^-1
- (B) 3.0 x 10^-5 s^-1
- (C) 1.5 x 10^-5 s^-1
- (D) 2.0 x 10^-5 s^-1

*71*. A certain zero order reaction has rate constant 0.025 M s^-1. What will be the concentration of reactant 'A' after 15 seconds, if initial concentration is 0.50 M?

- (A) 0.50 M
- (B) 0.125 M
- (C) 0.375 M
- (D) 0.060 M

*72*. The reaction A + B → P, is second order in A and first order in B. What is the rate law for the reaction?

- (A) Rate = k[A] [B]
- (B) Rate = k[A]² [B]^1/2
- (C) Rate = k[A]² [B]
- (D) Rate = k[A] [B]²

*73.*A first order reaction is 50 % completed in 50 minutes. What is the rate constant of the reaction?

- (A) 7.215 x 10^-1 min^-1
- (B) 3.465 x 10^-2 min^-1
- (C) 1.386 x 10^-2 min^-1
- (D) 1.386 x 10^-1 min^-1

*74*. A first order reaction takes 40 minutes for 30% completion. Calculate the half-life of reaction

- (A) 77.7 min
- (B) 23.1 min
- (C) 42.7 min
- (D) 57.8 min

*75*. Rate constant for zero order reaction is 2 x 10^-2 mol^-1 s^-1. If the concentration of the reactant after 25 sec. is 0.5 M, what is the initial concentration of reactant?

- (A) 0.125 M
- (B) 0.5 M
- (C) 1.25 M
- (D) 1.0 M

*76*. The slope of a graph. log [A]t versus 't' for a first order reaction is - 2.5 x 10^-3 s^-1. The rate constant for the reaction is

- (A) - 2.5 x 10^-3 s^-1
- (B) 2.5 x 10^-3 s^-1
- (C) 1.086 x 10^-3 s^-1
- (D) 5.757 x 10^-3 s^-1

77(78). A first order reaction, A → B takes 100 minutes for it's 90% completion. What is the rate constant of reaction?

- (A) 0.0460 min^-1
- (B) 0.0230 min^-1
- (D) 0.2303 min^-1
- (D) 0.4606 min^-1

*78*. 0.0210 M solution of N2O5 is allowed to decompose at 43°C. How long will it take to reduce 0.0150M ? (Given k = 6.0 x 10^-4 sec^-1)

- (A) 3364 sec
- (B) 360.0 sec
- (C) 560.0 sec
- (D) 5600 sec

*79*. The rate of first order reaction A → B is 6.3 x 10^-6 M s^-1, if [A] = 0.3 M, what is the rate constant of the reaction?

- (A) 1.3 x 10^-5 s^-1
- (B) 2.1 x 10^-5 s^-1
- (C) 1.2 x 10^-5 s^-1
- (D) 1.6 x 10^-5 s^-1

*80*. For zero order reaction, when [A]t is plotted against time (t), the slope of the straight line obtained is equal to

- (A) -k
- (B) -kt
- (C) k
- (D) [A]0

*81*. A first order reaction is 50 % completed in 16 minutes. The percentage of reactant that will react in 32 minutes is

- (A) 75 %
- (B) 12-5%
- (C) 25%
- (D) 100%

*82.*Consider the reaction; 2N2O5(g) → 4NO2(g) + O2(g). What is the rate of reaction, when the concentration of NO2 increases to 5.2 x 10^-3 M in 100 sec?

- (A) 2 x 10^-5 M/s
- (B) 7.6 x 10^-4 M/s
- (C) 5 x 10^-4 M/s
- (D) 1.3 x 10^-5 M/s

*83.*For the reaction 2A + B → 3C + D, which among the following is NOT the correct rate law expression ?

- (A) -d[A]/2dt
- (B) -d[B]/dt
- (C) d[D]/dt
- (D) -d[C]/3dt

*84*. The time required to decompose SO

_{2}Cl

_{2}to half of it's initial amount is 60 minutes. Calculate rate constant for the first order reaction.

- (A) 4.158 x 10^-2 min^-1
- (B) 2.651 x 10^-2 min^-1
- (C) 1.155 x 10^-2 min^-1
- (D) 1.551 x 10^-2 min^-1

*85.*The rate constant for the first order reaction is 1.15 x 10^-3 s^-1. How long will 5g of the reactant take to reduce to 3g?

- (A) 414 sec
- (B) 444 sec
- (C) 424 sec
- (D) 434 sec

*86*. When the temperature of first order reaction increases then according to Arrhenius equation which among the following is correct?

- (A) e - Ea/RT decreases
- (B) Ea/RT increases
- (C) -Ea/RT decreases
- (D) k decreases