Advertisements
Advertisements
प्रश्न
Define the half-life of a first-order reaction.
उत्तर
The time in which concentration of reactant becomes half of its initial concentration is called half Life. It is denoted by `t_(1/2)`.
APPEARS IN
संबंधित प्रश्न
Answer the following in one or two sentences.
What are the units for rate constants for zero-order and second-order reactions if time is expressed in seconds and concentration of reactants in mol/L?
Solve
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?
Time required for 100% completion of a zero order reaction is _______.
Write order of the following reaction:
\[\ce{2NH_{3(g)} -> N_{2(g)} + 3H_{2(g)}}\]
Write a mathematical expression for integrated rate law for zero-order reaction.
What is half life of first order reaction if time required to decrease concentration of reactants from 0.8 M to 0.2 M is 12 hours?
Derive an integrated rate law expression for first order reaction: A → B + C
This reaction follows first-order kinetics. The rate constant at particular temperature is 2.303 × 10−2 hour−1. The initial concentration of cyclopropane is 0.25 M. What will be the concentration of cyclopropane after 1806 minutes? (log 2 = 0.3010)
Describe the graphical representation of first order reaction.
Write the rate law for the following reaction.
A reaction that is second order in NO and first order in Br2.
Give two examples for zero order reaction.
The time for half change in a first order decomposition of a substance A is 60 seconds. Calculate the rate constant. How much of A will be left after 180 seconds?
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 is 25% completed in 40 minutes. What is the rate constant k tor the reaction?
Which among the following reaction is an example of a zero order reaction?
For a zero order reaction, the plot of [A]t vs t is linear. The slope of the line is equal to ____________.
The half-life of a first order reaction is 6.0 hour. How long will it take for the concentration of reactant to decrease from 0.4 M to 0.12 M?
A first order reaction takes 40 minutes for 30% decomposition. What is the half-life of reaction?
In a reaction \[\ce{N2_{(g)} + 3H2_{(g)} -> 2NH3_{(g)}}\], if the rate of disappearance of N2(g) is 2.6 × 10−4 M/s, the rate of disappearance of H2(g) in M/s is ____________.
A first order reaction takes 40 minutes for 30% completion. Calculate the half-life of reaction.
For the first order reaction A → B, the rate constant is 0.25 s-1, if the concentration of A is reduced to half, the value of rate constant will be ________.
For zero order reaction, when [A]t is plotted against time (t), the slope of the straight line obtained is equal to ______.
Which one of the following reactions is a true first-order reaction?
If the rate constant for a first-order reaction is k, the time (t) required for the completion of 99% of the reaction is given by:
The rate constant and half-life of a first order reaction are related to each other as ______.
Consider the following reaction.
\[\ce{SO2(g) + 1/2 O2(g) <=>[K1] SO3(g)}\]
\[\ce{2SO3(g)<=>[K2] 2SO2(g) + O2(g)}\]
What is the relation between K1 and K2?
A radioactive isotope decayed to 17/32 of its original mass after 60 minutes. Find the half-life of this radioisotope.