Advertisements
Advertisements
प्रश्न
In a first-order reaction, the concentration of the reactant decreases from 20 mmol dm−3 to 8 mmol dm−3 in 38 minutes. What is the half-life of reaction?
Advertisements
उत्तर
Given:
[A]0 = 20 m mol dm−3,
[A]t = 8 m mol dm−3,
t = 38 min
To find:
Half-life of reaction t1/2 = ?
Formulae:
i. `k = 2.303/t log_10 [A]_0/[A]_t`
ii. t1/2 = `0.693/k`
Calculation:
Substituting given value in
`k = 2.303/t log_10 [A]_0/[A]_t`
`k = 2.303/(38 min) log_10 20/8`
= `2.303/(38 min) log_10 (2.5)`
= `2.303/(38 min) xx 0.3979`
= 0.0241 min−1
t1/2 = `0.693/k`
= `0.693/0.0241`
= 28.7 min
The half life of reaction is 28.7 min.
APPEARS IN
संबंधित प्रश्न
How will you represent first order reactions graphically.
Answer the following in brief.
What is a zeroth-order reaction?
Solve
The half-life of a first-order reaction is 1.7 hours. How long will it take for 20% of the reactant to react?
Answer the following in brief.
What are the units of the rate constant?
Give one example of a pseudo first-order reaction.
A zero-order reaction \[\ce{X -> Product}\], with an initial concentration 0.02 M has a half-life of 10 min. if one starts with concentration 0.04 M, then the half-life is
Write the rate law for the following reaction.
A reaction that is second order in NO and first order in Br2.
Identify the order for the following reaction.
Radioactive disintegration of 92U238
A first order reaction is 25% completed in 40 minutes. What is the rate constant k tor the reaction?
A reaction that is of the first order with respect to reactant A has a rate constant 6 min−1. If we start with [A]0 = 0.5 mol dm−3, when would [A] reach the value 0.05 mol dm−3?
The time of completion of 90% of a first order reaction is approximately ____________.
In a first order reaction, the concentration of the reactant is reduced to 25% in one hour. The half-life period of the reaction is ____________.
If time required to decrease concentration of reactant from 0.8 M to 0.2 M is 12 hours, the half life of this first order reaction is ____________.
For the first order reaction, plot of log10 [A]t against time 't' is a straight line with a negative slope equal to ____________.
A first order reaction is 75% completed in 60 minutes, the time required for it's 50% completion is ____________.
For a zero order reaction, the plot of [A]t vs t is linear. The slope of the line is equal to ____________.
A first order reaction takes 40 minutes for 30% completion. Calculate the half-life of reaction.
The time required to decompose SO2Cl2 to half of it's initial amount is 60 minutes. Calculate rate constant for this first order reaction.
A certain zero order reaction has rate constant 0.025 M s-1. What will be the concentration of reactant 'A' after 15 seconds, if initial concentration is 0.50 M?
Half-life of first order reaction is 20 minutes. What is the time taken to reduce the initial concentration of the reactant to `1/10`th?
The integrated rate law is a direct relationship between time and ______
Obtain the expression for half-life and rate constant of the first-order reaction.
Which one of the following reactions is a true first-order reaction?
The rate constant and half-life of a first order reaction are related to each other as ______.
Which of the following is correct for a first-order reaction?
Calculate half-life of a first order reaction in minute if the rate constant is 1 × 10-3 s-1.
The half-life of first order reaction is 1.7 hour. What is its rate constant?
What are integrated rate laws?
If the half-life of a first-order reaction is 10 minutes, find the time required to decrease the concentration of the reactant from 0.08 M to 0.02 M.
