Advertisements
Advertisements
Question
Obtain the expression for half-life and rate constant of the first-order reaction.
Solution
k = `2.303/t log_10 [A]_0/[A]_t`
Where, `[([A]_0 = "Initial concentration"),([A]_t = "Final concentration")]`
At, t = `t_(1/2), [A]_t = [A]_0/2`
k = `2.303/t_(1/2) log_10 [A]_t/([A]_0/2)`
k = `2.303/t_(1/2) xx log_10 2`
= `2.303/t_(1/2) xx 0.3010`
`t_(1/2) = 0.693/k`
APPEARS IN
RELATED QUESTIONS
Answer the following in brief.
How will you represent the zeroth-order reaction graphically?
Answer the following in brief.
Derive the integrated rate law for the first-order reaction.
For the reaction 2NOBr → 2NO2 + Br2, the rate law is rate = k[NOBr]2. If the rate of a reaction is 6.5 × 10–6 mol L–1 s–1, when the concentration of NOBr is 2 × 10–3 mol L–1. What would be the rate constant of the reaction?
Derive an expression for the relation between half-life and rate constant for first-order reaction.
The decomposition of phosphine (PH3) on tungsten at low pressure is a first-order reaction. It is because the
Assertion: rate of reaction doubles when the concentration of the reactant is doubles if it is a first-order reaction.
Reason: rate constant also doubles.
A zero order reaction is 20% complete in 20 minutes. Calculate the value of the rate constant. In what time will the reaction be 80% complete?
A first order reaction has a rate constant 0.00813 min-1. How long will it take for 60% completion?
What is the value of rate constant of first order reaction, if it takes 15 minutes for consumption of 20% of reactants?
For first order reaction the concentration of reactant decreases from 0.2 to 0.1 M in 100 minutes. What is the rate constant of the reaction?
The time of completion of 90% of a first order reaction is approximately ____________.
A first order reaction completes its 10% in 20 minutes, then the time required to complete its 19% is ____________.
If [A]0 is the initial concentration, then the half life of zero order reaction is ____________.
The activation energy of a reaction is zero. Its rate constant at 280 K is 1.6 × 10-6 s-1, the rate constant at 300 K is ______.
Half-life period of a first order reaction, \[\ce{A -> product}\] is 3.0 hours. What is the value of rate constant?
A first order reaction is 75% completed in 60 minutes, the time required for it's 50% completion is ____________.
The slope of a graph, log [A]t versus 't' for a first order reaction is −2.5 × 10−3 s−1. The rate constant for the reaction is ____________.
A first order reaction takes 40 minutes for 30% completion. Calculate the half-life of reaction.
0.0210 M solution of N2O5 is allowed to decompose at 43°C. How long will it take to reduce to 0.0150 M?
(Given k = 6.0 × 10−4 sec−1)
Half-life of first-order reaction \[\ce{X -> Y + Z}\] is 3 minutes. What is the time required to reduce the concentration of 'X' by 90 % of it's initial concentration?
Rate constant for zero order reaction is 2 × 10-2 mol L-1 s-1. If the concentration of the reactant after 25 sec. is 0.5 M, what is the initial concentration of reactant?
The expression to calculate time required for completion of zero order reaction is ______.
The rate constant and half-life of a first order reaction are related to each other as ______.
Which of the following reactions is not of the first order?
The rate constant for a first order reaction is 7.0 × 10-4 s-1. If initial concentration of reactant is 0.080 M, what is the half-life of reaction?
Calculate half-life of a first order reaction in minute if the rate constant is 1 × 10-3 s-1.
The half-life period for the first order reaction is 1.7 hrs. How long will it take for 20% of the reactant to disappear?