Chemical Kinetics Test 4

Total Questions:50 Total Time: 75 Min

Remaining:

 

Questions 1 of 50

Question:The rate of a gaseous reaction is given by the expression \(K\,[A]\,[B]\). If the volume of the reaction vessel is suddenly reduced to 1/4th of the initial volume, the reaction rate relating to original rate will be

Answers Choices:

1/10

1/8

8

16

Questions 2 of 50

Question:A catalyst increases the rate of reaction because it

Answers Choices:

Increases the activation energy

Decreases the energy barrier for reaction

Decreases the collision diameter

Increases the temperature coefficient

Questions 3 of 50

Question:For the reaction \({N_2}(g) + 3{H_2}(g) \to 2N{H_3}(g)\) under certain conditions of temperature and partial pressure of the reactants, the rate of formation of \(N{H_3}\) is \(0.001\,kg\,{h^{ - 1}}\). The rate of conversion of \({H_2}\) under the same conditions is

Answers Choices:

\(1.82\, \times {10^{ - 4}}\,kg/hr\)

\(0.0015\,kg/hr\)

\(1.52 \times {10^4}kg/hr\)

\(1.82 \times {10^{ - 14}}kg/hr\)

Questions 4 of 50

Question:A catalyst increases the rate of a chemical reaction by

Answers Choices:

Increasing the activation energy

Decreasing the activation energy

Reacting with reactants

Reacting with products

Questions 5 of 50

Question:Velocity constant of a reaction at 290 K was found to be \(3.2 \times {10^{ - 3}}\) . At 310 K it will be about

Answers Choices:

\(1.28 \times {10^{ - 2}}\)

\(9.6 \times {10^{ - 3}}\)

\(6.4 \times {10^{ - 3}}\)

\(3.2 \times {10^{ - 4}}\)

Questions 6 of 50

Question:The temperature coefficient of a reaction is

Answers Choices:

Specific reaction rate at \({25^o}C\)

Rate of the reaction at \({100^o}C\)

Ratio of the rate constants at temperatures \({35^o}C\)and \({25^o}C\)

Ratio of the rate constants at two temperatures differing by \({1^o}C\)

Questions 7 of 50

Question:The rate law for the reaction Sucrose + Water \( \to \) Glucose + Fructose is given by

Answers Choices:

Rate \( = K\)[sucrose] [water]

Rate \( = K\)[sucrose] [water]\(^0\)

Rate \( = K\)[sucrose]\(^0\)[water]

Rate \( = K\)[sucrose]\(^{1/2}\)[water]\(^{1/2}\)

Questions 8 of 50

Question:\(A + 2B \to C + D\). If \( - \frac{{d[A]}}{{dt}} = 5 \times {10^{ - 4}}mol\,{l^{ - 1}}{s^{ - 1}}\)1, then \( - \frac{{d[B]}}{{dt}}\) is

Answers Choices:

\(2.5 \times {10^{ - 4}}mol\,{l^{ - 1}}{s^{ - 1}}\)

\(5.0 \times {10^{ - 4}}mol\,{l^{ - 1}}{s^{ - 1}}\)

\(2.5 \times 10 - 3mol\,{l^{ - 1}}{s^{ - 1}}\)

\(1.0 \times {10^{ - 3}}mol\,{l^{ - 1}}{s^{ - 1}}\)

Questions 9 of 50

Question:The reaction \(2NO(g) + {O_2}(g)\)\( \leftrightarrow \)\(2N{O_2}(g)\)is of first order. If volume of reaction vessel is reduced to 1/3, the rate of reaction would be

Answers Choices:

1/3 times

2/3 times

3 times

6 times

Questions 10 of 50

Question:The reaction \({N_2}{O_5}\,({\rm{in}}\,CC{l_4}\,{\rm{solution}}) \to 2N{O_2}({\rm{solution}}) + \frac{1}{2}{O_2}(g)\) is of first order in \({N_2}{O_5}\) with rate constant \(6.2 \times {10^{ - 1}}{s^{ - 1}}.\) What is the value of rate of reaction when \([{N_2}{O_5}] = 1.25\,mole\,{l^{ - 1}}\)

Answers Choices:

\(7.75 \times {10^{ - 1}}mole\,{l^{ - 1}}{s^{ - 1}}\)

\(6.35 \times {10^{ - 3}}mole\,{l^{ - 1}}{s^{ - 1}}\)

\(5.15 \times {10^{ - 5}}mole\,{l^{ - 1}}{s^{ - 1}}\)

\(3.85 \times {10^{ - 1}}mole\,{l^{ - 1}}\,{s^{ - 1}}\)

Questions 11 of 50

Question:A reaction that is of the first order with respect to reactant A has a rate constant \(6{\min ^{ - 1}}.\) If we start with \([A] = 0.5\,mol\,\,{l^{ - 1}}\), when would \([A]\)reach the value 0.05mol \({l^{ - 1}}\)

Answers Choices:

0.384 min

0.15 min

min

3.84 min

Questions 12 of 50

Question:The rate constant for the reaction, \(2{N_2}{O_5} \to 4N{O_2}\)\( + {O_2}\) is \(3 \times {10^{ - 5}}{\sec ^{ - 1}}\). If the rate is \(2.40 \times {10^{ - 5}}mol\,\,litr{e^{{\rm{ - 1}}}}{\sec ^{ - 1}}\). Then the concentration of \({N_2}{O_5}\)(in mol litre-1) is

Answers Choices:

1.4

1.2

0.04

0.8

Questions 13 of 50

Question:For a chemical reaction \(A \to B\) it is found that the rate of reaction doubles, when the concentration of A is increased four times. The order in A for this reaction is

Answers Choices:

Two

One

Half

Zero

Questions 14 of 50

Question:The hydrolysis of ethyl acetate is a reaction of \(C{H_3}COOEt + {H_2}O \to C{H_3}COOH + EtOH\)

Answers Choices:

First order

Second order

Third order

Zero order

Questions 15 of 50

Question:The rate of reaction between \(A\) and \(B\) increases by a factor of 100, when the concentration of \(A\) is increased 10 folds. The order of reaction with respect to \(A\) is

Answers Choices:

10

1

4

2

Questions 16 of 50

Question:A first order reaction requires 30 minutes for 50% completion. The time required to complete the reaction by 75% will be

Answers Choices:

45 minutes

15 minutes

60 minutes

None of these

Questions 17 of 50

Question:Inversion of canesugar in dilute acid (conversion into glucose and fructose) is a

Answers Choices:

Unimolecular reaction

Bimolecular reaction

Trimolecular reaction

Pseudo-unimolecular reaction

Questions 18 of 50

Question:The half life period of a first order reaction

Answers Choices:

\(\frac{{0.693}}{t}\)

\(\frac{{0.693}}{K}\)

\(\frac{{2.303}}{t}\)

\(\frac{{0.303}}{{{K_1}}}\)

Questions 19 of 50

Question:Decomposition of nitrogen pentoxide is known to be a first order reaction 75 percent of the oxide had decomposed in the first 24 minutes. At the end of an hour, after the start of the reaction, the amount of oxide left will be

Answers Choices:

Nil

About 1%

About 2%

About 3%

Questions 20 of 50

Question:A reaction \(2A \to \) products is found to follow zero oder kinetics, then

Answers Choices:

\(\frac{{dx}}{{dt}} = k{[A]^2}\)

\(\frac{{dx}}{{dt}} = k{[A]^0}\)

\(\frac{{dx}}{{dt}} = k[A]\)

\(\frac{{dx}}{{dt}} = k[2A]\)

Questions 21 of 50

Question:The alkaline hydrolysis of ethyl acetate is represented by the equation \(C{H_3}COO{C_2}{H_5} + NaOH \to C{H_3}COONa + {C_2}{H_5}OH\) Experimentally it is found that for this reaction \(\frac{{dx}}{{dt}} = k[C{H_3}COO{C_2}{H_5}]\,[NaOH]\) Then the reaction is

Answers Choices:

Bimolecular and of first order

Bimolecular and of second order

Pseudo–bimolecular

Pseudo–unimolecular

Questions 22 of 50

Question:In the reaction \(A + B \to \) Products, if \(B\) is taken in excess, then it is an example of

Answers Choices:

Second order reaction

Zero order reaction

Pseudounimolecular reaction

First order reaction

Questions 23 of 50

Question:The half life of a first order reaction is \(69.35\,\sec \). The value of the rate constant of the reaction is

Answers Choices:

\(1.0\,{s^{ - 1}}\)

\(0.1\,{s^{ - 1}}\)

\(0.01\,{s^{ - 1}}\)

\(0.001\,{s^{ - 1}}\)

Questions 24 of 50

Question:The half life for the reaction \({N_2}{O_5}\)\( \leftrightarrow \) \(2N{O_2} + \frac{1}{2}{O_2}\) in \(24\,hrs\) at \({30^o}C\). Starting with \(10\,g\) of \({N_2}{O_5}\) how many grams of \({N_2}{O_5}\) will remain after a period of 96 hours

Answers Choices:

\(1.25\,g\)

\(0.63\,g\)

\(1.77\,g\)

\(0.5\,g\)

Questions 25 of 50

Question:For a first order reaction, the half-life period is independent of

Answers Choices:

Initial concentration

Cube root of initial concentration

First power of final concentration

Square root of final concentration

Questions 26 of 50

Question:Order of a reaction can have

Answers Choices:

\( + ve\) values

Whole number values

Fractional values

All of the above

Questions 27 of 50

Question:The order of the reaction occurring by following mechanism should be (i)\({A_2} \to A + A\) (fast) (ii)\(A + {B_2} \to AB + B\) (slow) (iii)\(A + B \to \) (fast)

Answers Choices:

\(1\,\frac{1}{2}\)

\(3\frac{1}{2}\)

2

None of these

Questions 28 of 50

Question:After how many seconds will the concentration of the reactants in a first order reaction be halved, if the decay constant is \({\rm{1}}{\rm{.155}} \times {\rm{1}}{{\rm{0}}^{{\rm{ - 3}}}}{\sec ^{ - 1}}\)

Answers Choices:

100 sec

200 sec

400 sec

600 sec

Questions 29 of 50

Question:What is the order of a reaction which has a rate expression rate \( = K{[A]^{3/2}}{[B]^{ - 1}}\)

Answers Choices:

2-Mar

2-Jan

0

None of these

Questions 30 of 50

Question:Which of the following expression is correct for first order reaction? \((CO)\) refers to initial concentration of reactant

Answers Choices:

\({t_{1/2}} \propto CO\)

\({t_{1/2}} \propto C{O^{ - 1}}\)

\({t_{1/2}} \propto C{O^{ - 2}}\)

\({t_{1/2}} \propto C{O^0}\)

Questions 31 of 50

Question:Units of rate constant of first and zero order reactions in terms of molarity M unit are respectively

Answers Choices:

\(se{c^{ - 1}},\,\,\,M\,se{c^{ - 1}}\)

\(se{c^{ - 1}},\,\,\,M\)

\(M\,se{c^{ - 1}},\,\,\,se{c^{ - 1}}\)

\(M,\,se{c^{ - 1}}\)

Questions 32 of 50

Question:The reaction \(2{N_2}{O_5}\) \( \leftrightarrow \) \(2{N_2}{O_4} + {O_2}\) is

Answers Choices:

Bimolecular and second order

Unimolecular and first order

Bimolecular and first order

Bimolecular and zero order

Questions 33 of 50

Question:The half-life period for a first order reaction is 693 seconds. The rate constants for this reaction would be

Answers Choices:

\(0.1se{c^{ - 1}}\)

\(0.01se{c^{ - 1}}\)

\(0.001se{c^{ - 1}}\)

\(0.0001se{c^{ - 1}}\)

Questions 34 of 50

Question:For an elementary reaction, 2A + B\( \to \) C + D the molecularity is

Answers Choices:

Zero

One

Two

Three

Questions 35 of 50

Question:Which of the following is an example of pseudo unimolecular reaction

Answers Choices:

\(C{H_3}COOC{H_3} + {H_2}O \to C{H_3}COOH + C{H_3}OH\)

\(C{H_3}COOC{H_3} + {H_2}O \to C{H_3}COOH + C{H_3}OH\)

\(2FeC{l_3} + SnC{l_2} \to SnC{l_4} + 2FeC{l_2}\)

\(NaOH + HCl \to NaCl + {H_2}O\)

Questions 36 of 50

Question:Hydrolysis of DDT is a first order reaction, its half life is 10 years. Time to hydrolyse 10 g DDT to half is

Answers Choices:

100 years

50 years

years

10 years

Questions 37 of 50

Question: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 is

Answers Choices:

7.5 minutes

15 minutes

30 minutes

60 minutes

Questions 38 of 50

Question:In the first order reaction, the concentration of the reactant is reduced to 25% in one hour. The half life period of the reaction is

Answers Choices:

hr

4 hr

1/2 hr

1/4 hr

Questions 39 of 50

Question:\({t_{\frac{1}{4}}}\) 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 \({t_{\frac{1}{4}}}\) can be written as

Answers Choices:

\(0.10/K\)

\(0.29/K\)

\(0.69/K\)

\(0.75/K\)

Questions 40 of 50

Question:For a first order reaction \(A \to B\) the reaction rate at reactant concentration of \(0.01M\) is found to be \(2.0 \times {10^{ - 5}}mol\;{L^{ - 1}}{s^1}\) . The half life period of the reaction is

Answers Choices:

220 s

30 s

300 s

347 s

Questions 41 of 50

Question:The rate of reaction between two reactants A and B decreases by a factor of 4 if the concentration of reactant B is doubled. The order of this reaction with respect to reactant B is

Answers Choices:

1

2

1

2

Questions 42 of 50

Question:If a substance with half life 3 days is taken at other place in 12 days. What amount of substance is left now

Answers Choices:

1/4

1/8

1/16

1/32

Questions 43 of 50

Question:The energy of activation is

Answers Choices:

The energy associated with the activated molecules

Threshold energy – energy of normal molecules

Threshold energy + energy of normal molecules

Energy of products – energy of reactants

Questions 44 of 50

Question:Which one of the following does not represent Arrhenius equation

Answers Choices:

\(k = A{e^{ - E/RT}}\)

\({\log _e}k = {\log _e}A - \frac{E}{{RT}}\)

\({\log _{10}}k = {\log _{10}}A - \frac{E}{{2.303\,RT}}\)

\(k = A{E^{ - RT}}\)

Questions 45 of 50

Question:On increasing the temperature, the rate of the reaction increases because of

Answers Choices:

Decrease in the number of collisions

Decrease in the energy of activation

Decrease in the number of activated molecules

Increase in the number of effective collisions

Questions 46 of 50

Question:Energy of activation of a reactant is reduced by

Answers Choices:

Increased temperature

Reduced temperature

Reduced pressure

Increased pressure

Questions 47 of 50

Question:Collision theory is applicable to

Answers Choices:

First order reactions

Zero order reactions

Bimolecular reactions

Intra molecular reactions

Questions 48 of 50

Question:The rate constant of a reaction at temperature 200K is 10 times less than the rate constant at 400 K. What is the activation energy \(({E_a})\)of the reaction (R = gas constant)

Answers Choices:

1842.4 R

921.2 R

460.6 R

230.3 R

Questions 49 of 50

Question:In respect of the equation \(k = A{e^{ - {E_a}/RT}}\) in chemical kinetics, which one of the following statement is correct

Answers Choices:

k is equilibrium constant

A is adsorption factor

\({E_a}\)is energy of activation

R is Rydberg’s constant

Questions 50 of 50

Question:The rate constant is doubled when temperature increases from 27\(^\circ \)C to 37\(^\circ \)C. Activation energy in kJ is

Answers Choices:

34

54

100

50