The time for half-life period of a certain reaction, A longrightarrow products is 1 h. When the initial concentration of the reactant ' A ' is 2.0 mol L -1, how much time does it take for its concentration to come from 0.50 to 0.25 mol L -1, if it is a zero-order reaction?

Question

The time for half-life period of a certain reaction, A longrightarrow products is 1 h. When the initial concentration of the reactant ' A ' is 2.0 mol L -1, how much time does it take for its concentration to come from 0.50 to 0.25 mol L -1, if it is a zero-order reaction? (A) 4 h (B) 0.5 h (C) 0.25 h (D) 1 h

Tardigrade Admin · Accepted Answer

Half-life for a zero-order reaction is given by

t_{1/2} = \frac{[ A _{0} ]}{2 k}

[where [A_{0}] = initial concentration of reactan

\Rightarrow k_{0} = \frac{[ A ] _{0}}{2 t _{1/2}} = \frac{2.0 m o l L ^{- 1}}{2 \times 1 h} = 1.0 m o l L^{- 1} h^{- 1}

Rate constant for a zero-order reaction is given by

k = \frac{1}{t} [A_{0}) - (A)]

\Rightarrow t = \frac{1}{k} [(A_{0}) - (A)]

t = \frac{( 0.50 ) - ( 0.25 ) m o l L ^{- 1}}{1 m o l L ^{- 1} h ^{- 1}}

\Rightarrow t = 0.25 h

Q. The time for half-life period of a certain reaction, $A ⟶$ products is $1 h$ . When the initial concentration of the reactant ' $A$ ' is $2.0 m o l L^{- 1}$ , how much time does it take for its concentration to come from $0.50$ to $0.25 m o l L^{- 1}$ , if it is a zero-order reaction?

$4 h$

$0.5 h$

$0.25 h$

$1 h$

Q. The time for half-life period of a certain reaction, A⟶ products is 1h. When the initial concentration of the reactant ' A ' is 2.0molL−1, how much time does it take for its concentration to come from 0.50 to 0.25molL−1, if it is a zero-order reaction?

4h

0.5h

0.25h

1h

Q. The time for half-life period of a certain reaction, $A ⟶$ products is $1 h$ . When the initial concentration of the reactant ' $A$ ' is $2.0 m o l L^{- 1}$ , how much time does it take for its concentration to come from $0.50$ to $0.25 m o l L^{- 1}$ , if it is a zero-order reaction?

$4 h$

$0.5 h$

$0.25 h$

$1 h$