# When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction is: Option 1) Second Option 2) More than zero but less than first Option 3) Zero Option 4) First

As learnt

First Order Reaction -

The rate of the reaction is proportional to the first power of the concentration of the reaction

- wherein

Formula:

R    $\rightarrow$        P

a                 0

a-x             x

$rate[r]=K[R]^{1}$

$\frac{-d(a-x)}{dt}=K(a-x)$

$\frac{-dx}{dt}=K(a-x)$  [differentiate rate law]

$ln \:[\frac{a}{a-x}]=kt \:(Integrated rate law)$

Unit of $k=sec^{-1}$

$t_\frac{1}{2}=\frac{0.693}{k}$

Half period of a first order reaction is independent of initial concentration.

$t_{\frac{1}{2}}=\frac{0.693}{K}$

Option 1)

Second

This option is incorrect

Option 2)

More than zero but less than first

This option is incorrect

Option 3)

Zero

This option is incorrect

Option 4)

First

This option is correct

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