The time for half life period of a certain reaction A → products is 1 hour. 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 → products is 1 hour. 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

For a zero order reaction k = (x/t ) →(1) Where x = amount decomposed k = zero order rate constant for a zero order reaction k = ([A]0/2t(t)2) → (2) Since [A0] = 2M , t1/2 = 1 hr; k = 1 ∴ from equation (1) t = (0.25/1) = 0.25 hr

Q. The time for half life period of a certain reaction $A \to$ products is $1$ hour. 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 ?

$4 h$

$0.5 h$

$0.25 h$

$1 h$

For a zero order reaction $k = \frac{x}{t} \to (1)$
Where x = amount decomposed
k = zero order rate constant for a zero order reaction
$k = \frac{[ A ] _{0}}{2 t _{\frac{t}{2}}} \to (2)$
Since $[A_{0}] = 2 M, t_{1/2} = 1 h r; k = 1$
$∴$ from equation $(1)$
$t = \frac{0.25}{1} = 0.25 h r$

Q. The time for half life period of a certain reaction A→ products is 1 hour. 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