The half life period of a first order reaction is given by (where, K = rate constant. )

The half life period of a radioactive substance is best determined by counting the number of alpha particles emitted per second in a Geiger Muller counter from its known quantity. If the half life period of a radioactive substance is one month, then

A

$${\frac{3}{4}^{{\text{th}}}}$$ of it will disintegrate in two months

B

It will completely disintegrate in two months

C

It will completely disintegrate in four months

D

$${\frac{l}{8}^{{\text{th}}}}$$ of it will remain intact at the end of four months

A man sells chocolates which are in the boxes. Only either full box or half a box of chocolates can be purchased from him. A customer comes and buys half the number of boxes which the seller had plus half box more. A second customer comes and purchases half the remaining number of boxes plus half a box. After this the seller is left with no chocolate boxes. How many chocolate boxes the seller had initially?

A

2

B

3

C

4

D

3.5

E

None of these

The knowledge of initial concentration and rate constant is necessary to determine the half life time of a reaction of __________ order.

A

Zero

B

First

C

Second

D

None of these

The conversion of a reactant, undergoing a first order reaction, at a time equal to three times the half life of the reaction is

A

0.875

B

0.5

C

0.425

D

Data insufficient to calculate

The half life period of a first order reaction is

A

Always the same irrespective of the reaction

B

Dependent on initial concentration of the reactants

C

Proportional to the initial concentration of reactants

D

Half the specific rate constant

Half life period of a first order irreversible reaction A → B is

A

$$\frac{{\text{k}}}{2}$$

B

$$\ln \frac{{\text{k}}}{2}$$

C

$$\ln \frac{2}{{\text{k}}}$$

D

$$\ln \frac{{{\text{0}}{\text{.5}}}}{{\text{k}}}$$

Half-life period for a first order reaction is __________ the initial concentration of the reactant.

A

Directly proportional to

B

Inversely proportional to

C

Independent of

D

None of these

For a __________ order reaction, the units of rate constant and rate of reaction are the same.

A

Zero

B

First

C

Second

D

Fractional

What is the order of a chemical reaction in which doubling the initial concentration of the reactants doubles the half life time of the reaction?

A

0

B

1

C

2

D

3

In order to have constant chain reaction to produce a constant rate of heat output, the value of ratio of the number of neutrons in one generation to the number of neutrons in the immediately preceding generation must be

A

Greater than 1.0

B

Less than 1.0

C

Equal to zero

D

Equal to 1.0

The half life period of a first order reaction is given by (where, K = rate constant. )

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