Chem Brain

Question#1

A first order reaction complete its 10% in 20 minutes then time required to complete its 19% is [Kerala CET 2005]

30 minutes

40 minutes

50 minutes

38 minutes

45 minutes

Please select an option

Question#2

Please select an option

Question#3

Rate of reaction [Pb. CET 2004]

Decreases with increase in temperature

Increases with increase in temperature

May increase or decrease with increase in temperature

Does not depend on temperature

Please select an option

Question#4

In which of the following cases, does the reaction go farthest to completion [UPSEAT 2001]

K = 10³

K = 10²

K = 10

K = 1

Please select an option

Question#5

The velocity constant of a reaction at 290 K was found to be 3.2 x 10^-3 . At 300 K it will be [MP PMT 2004]

1.28 x 10^-2

6.4 x 10^-3

9.6 x 10^-3

3.2 x 10^-4

Please select an option

Question#6

Which reaction characteristics are changing by the addition of a catalyst to a reaction at constant temperature

(i) Activation energy

(ii) Equilibrium constant

(iii) Reaction entropy

(iv) Reaction enthalpy

[DCE 2003]

(i) Only

(iii) only

(i) and I(ii) only

All of these

Please select an option

Question#7

A reaction is catalysed by ‘X ’. Here ‘X ’ [MP PMT 2003]

Decreases the rate constant of reaction

Does not affect the equilibrium constant of reaction

Decreases the enthalpy of reaction

Decreases the activation energy

Please select an option

Question#8

Which of the following statements is false in relation to enzyme [MP PMT 2003]

pH affects their functioning

Temperature affects their functioning

They always increase activation energy

Their reactions are specific

Please select an option

Question#9

The rate of a reaction [CPMT 1973]

Increases with increase in temperature

Decreases with increase in temperature

Does not depend on temperature

Does not depend on concentration

Please select an option

Question#10

The main function of a catalyst in speeding up a reaction is

To increase the rate of the forward reaction

To change the reaction path so as to decrease the energy of activation for the reaction

To reduce the temperature at which the reaction can occur

To increase the energy of the molecules of the reactants

Please select an option

Question#11

The temperature coefficient of a reaction is

Specific reaction rate at 25^oC

Rate of the reaction at 100^oC

Ratio of the rate constants at temperatures 35^oC and 25^oC

Ratio of the rate constants at two temperatures differing by 1^oC

Please select an option

Question#12

Velocity constant of a reaction at 290 K was found to be 3.2 x 10^-3. At 310 K it will be about [KCET 1989, 91]

1.28 x 10^-2

9.6 x 10^-3

6.4 x 10^-3

3.2 x 10^-4

Please select an option

Question#13

A catalyst increases the rate of a chemical reaction by [MNR 1988; CPMT 1999; Pb. PMT 2000]

Increasing the activation energy

Decreasing the activation energy

Reacting with reactants

Reacting with products

Please select an option

Question#14

The rate of a reaction is doubled for every 10^o rise in temperature. The increase in reaction rate as a result of temperature rise from 10^o to 100^o is [KCET 1993; Kerala PET 2002; MP PET 2003]

112

512

400

614

Please select an option

Question#15

The temperature coefficient for reaction in which food deteriorates is 2. Then food deteriorates ...... times as rapidly at 25^oC as it does at 5^oC

Two

Four

Six

Twenty

Please select an option

Question#16

An increase in temperature by 10^oC generally increases the rate of a reaction by [MP PET 1994; CBSE PMT 2000]

2 times

10 times

9 times

100 times

Please select an option

Question#17

The velocity of the chemical reaction doubles every 10^oC rise of temperature. If the temperature is raised by 50^oC, the velocity of the reaction increases to about

32 times

16 times

20 times

50 times

Please select an option

Question#18

Doubled

Decreased by half

Unchanged

Increased by four times

Please select an option

Question#19

0.64 x 10^-3 g /sec

0.80 x 10^-3 g /sec

1.28 x 10^-3 g /sec

1.60 x 10^-3 g /sec

Please select an option

Question#20

The rate of a chemical reaction depends upon [AFMC 2002]

Time

Pressure

Concentration

All of these

Please select an option

Question#21

Please select an option

Question#22

Please select an option

Question#23

None of these

Please select an option

Question#24

The rate of a reaction depends upon the [Pb. PMT 1999]

Volume

Force

Pressure

Concentration of reactant

Please select an option

Question#25

Concentration of the reactant

Decrease in concentration of the reactant with time

Increase in concentration of the reactant with time

Velocity constant of the reaction

Please select an option

Question#26

Increase by four times

Decrease by two times

Increase by two times

Remain the same

Please select an option

Question#27

1.82 x 10^-4 kg / hr

0.0015kg / hr

1.52 x 10⁴ kg / hr

1.82 x 10^-14 kg / hr

Please select an option

Question#28

A catalyst increases the rate of reaction because it [EAMCET 1992]

Increases the activation energy

Decreases the energy barrier for reaction

Decreases the collision diameter

Increases the temperature coefficient

Please select an option

Question#29

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[Roorkee 1992]

1/10

1/8

8

16

Please select an option

Question#30

Half the rate that B will decrease

The same rate that B will decrease

Twice the rate that B will decrease

The same rate that A₂B will form

Please select an option

Question#31

Increase 2 times

Increase 4 times

Decrease 2 times

Decrease 4 times

Please select an option

Question#32

Time required for completion of ionic reactions in comparison to molecular reactions is

Maximum

Minimum

Equal

None

Please select an option

Question#33

If the concentration of the reactants is increased, the rate of reaction [MP PMT 1989]

Remains unaffected

Increases

Decreases

May increase or decrease

Please select an option

Question#34

In a catalytic conversion of N₂ to NH₃ by Haber's process, the rate of reaction was expressed as change in the concentration of ammonia per time is 40 x 10^-3 mollitre^-1 s^-1. If there are no side reaction, the rate of the reaction as expressed in terms of hydrogen is (in mollitre^-1 s^-1 )

60 x 10^-3

20 x10^-3

1.200

10.3 x 10^-3

Please select an option

Question#35

When a reaction is progressing

The rate of the reaction goes on increasing

The concentration of the products goes on decreasing

The concentration of the reactants goes on decreasing

The reaction rate always remains constant

Please select an option

Question#36

The concentration of a reactant decreases from 0.2 M to 0.1 M in 10 minutes. The rate of the reaction is

0.01 M

10^-2

0.01 mol dm^-3 min¹

1 mol dm^-3 min¹

Please select an option

Question#37

The rate of chemical reaction at constant temperature is proportional to

The amount of products formed

The product of masses of the reactants

The product of the molar concentration of the reactants

The mean free path of the reaction

Please select an option

Question#38

If doubling the concentration of a reactant `A' increases the rate 4 times and tripling the concentration of `A' increases the rate 9 times, the rate is proportional to [AIIMS 1991]

Concentration of `A'

Square of concentration of `A'

Under root of the concentration of `A'

Cube of concentration of `A'

Please select an option

Question#39

Doubled on doubling the concentration of sodium hydroxide

Halved on reducing the concentration of alkyl halide to one half

Decreased on increasing the temperature of the reaction

Unaffected by increasing the temperature of the reaction

Please select an option

Question#40

The rate at which a substance reacts depends on its [MP PMT 1987; BHU 1999; KCET 2005]

Atomic weight

Equivalent weight

Molecular weight

Active mass

Please select an option

Question#41

The rate of a reaction that not involve gases is not dependent on [CPMT 1988; AFMC 1995]

Pressure

Temperature

Concentration

Catalyst

Please select an option

Question#42

The rate of a chemical reaction [MP PMT 1973; CPMT 1982]

Increases as the reaction proceeds

Decreases as the reaction proceeds

May increase or decrease during the reaction

Remains constant as the reaction proceeds

Please select an option

Question#43

The rate of a chemical reaction depends upon [AFMC 2002]

Time

Pressure

Concentration

All of these

Please select an option

Question#44

A gaseous hypothetical chemical $2 A \leftrightarrow 4 B + C$ is carried out in a closed vessel. The concentration of B is found to increase by 5 x 10^-3mol l^-1 in 10 second. The rate of appearance of B is [AFMC 2001]

5 x 10 ^-4 mol l^-1sec^-1 5 x 10 ^-5 mol l^-1sec^-1

6 x 10 ^-5 mol l^-1sec^-1

4 x 10 ^-4 mol l^-1sec^-1

Please select an option

Question#45

For the reaction $N_{2} + 3 H_{2} \to 2 N H_{3}$ if $\frac{Δ [N H_{3}]}{Δ t}$ =2 x 10^-4mol l^- s^- , the value of $- \frac{Δ H_{2}}{Δ t}$ would be [MP PMT 2000]

1 x 10^-4mol l^-1s^-1

3 x 10^-4mol l^-1s^-1

4 x 10^-4mol l^-1s^-1

6 x 10^-4mol l^-1s^-1

Please select an option

Question#46

For a given reaction $3 A + B \to C + D$ the rate of reaction can be represented by [DCE 2000]

$- \frac{Δ [A]}{3 Δ t} = - \frac{Δ [B]}{Δ t} = + \frac{Δ [C]}{Δ t} = + \frac{Δ [D]}{Δ t}$

$- \frac{Δ [A]}{3 Δ t} = \frac{Δ [C]}{Δ t} = K [A]^{m} [B]^{n}$

$+ \frac{Δ [A]}{3 Δ t} = - \frac{Δ [C]}{Δ t} = K [A]^{m} [B]^{n}$

None of these

Please select an option

Solution:

$- \frac{Δ [A]}{3 Δ t} = - \frac{Δ [B]}{Δ t} = + \frac{Δ [C]}{Δ t} = + \frac{Δ [D]}{Δ t}$

Question#47

The term $- \frac{d t}{d c}$ in a rate equation refers to the [MP PMT 1996]

Concentration of the reactant

Decrease in concentration of the reactant with time

Increase in concentration of the reactant with time

Velocity constant of the reaction

Please select an option

Question#48

For the reaction $N_{2} + 3 H_{2} \to 2 N H_{3}$ g under certain conditions of temperature and partial pressure of the reactants, the rate of formation of NH₃ is 0.001 kg h^-1. The rate of conversion of H₂under the same conditions is [IIT 1994]

1.82 x10^-4 kg / hr

0.0015 kg / hr

1.52 x10⁴ kg / hr

1.82 x10¹⁴ kg / hr

Please select an option

Question#49

How will be the rate of reaction, if the slop of the curve is greater near the start of reaction. MDCAT2023

Constant

Equilibrium

Greater

lesser

Please select an option

Question#50

Rate of reaction between two specific time intervals is called [MDCAT2023]

Instantaneous rate of reaction

rate of reaction

average rate of reaction

initial rate of reaction

Please select an option

Question#51

Which is not true about rate of reaction ? NUMS2021

It is independent of concentration of reactants

It depends upon temperature

It depends upon the order of reaction

All of the above options are correct

Please select an option

Question#52

When the change in concentration is 6 x 10^-4moldm^-3 and time for that change in 10 seconds, the rate of reaction will be MDCAT2015

6 x 10^-3moldm^-3Sec^-1

6 x 10^-2moldm^-3Sec^-1

6 x 10^-4moldm^-3Sec^-1

6 x 10^-5moldm^-3Sec^-1

Please select an option

Question#53

The reaction rate in forward direction decreases with the passage of time because MDCAT2012

Concentration of reactants decreases

The order of reaction changes

Concentration of product decreases

Temperature of the system changes

Please select an option

Question#54

The term $\frac{- Δ [A]}{Δ t}$ in a rate equation refers to the
[MP PMT 1996]

Concentration of the reactant

Decrease in concentration of the reactant with time

Increase in concentration of the reactant with time

Velocity constant of the reaction

Please select an option

Question#55

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[Roorkee 1992]

1/10

1/8

8

16

Please select an option

Question#56

If the concentration of the reactants is increased, the rate of reaction
[MP PMT 1989]

Remains unaffected

Increases

Decreases

May increase or decrease

Please select an option

Question#57

If doubling the concentration of a reactant `A' increases the rate 4
times and tripling the concentration of `A' increases the rate 9
times, the rate is proportional to [AIIMS 1991]

Concentration of `A'

Square of concentration of `A'

Under root of the concentration of `A'

Cube of concentration of `A'

Please select an option

Question#58

The rate at which a substance reacts depends on its
[MP PMT 1987; BHU 1999; KCET 2005]

Atomic weight

Equivalent weight

Molecular weight

Active mass

Please select an option

Question#59

The rate of a reaction that not involve gases is not dependent on [CPMT 1988; AFMC 1995]

Pressure

Temperature

Concentration

Catalyst

Please select an option

Question#60

The rate of a chemical reaction [MP PMT 1973; CPMT 1982]

Increases as the reaction proceeds

Decreases as the reaction proceeds

May increase or decrease during the reaction

Remains constant as the reaction proceeds

Please select an option

Home/Reaction kineticsRate of reaction

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Rate of reaction