Advertisements
Advertisements
Question
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?
Advertisements
Solution
1. Order of a reaction = 1
`"t"_(1/2)` = 60 seconds,
k = ?
We know that, k = `0.6932/"t"_(1/2)`
k = `2.303/60` = 0.01155 s−1
2. [A0] = 100%
t = 180 s
k = 0.01155 seconds−1
[A] = ?
For the first order reaction k = `2.303/"t" log (["A"_0])/(["A"])`
0.01155 = `2.303/180 log (100/(["A"]))`
`(0.01155 xx 180)/2.303 = log (100/(["A"]))`
0.9207 = log 100 – log [A]
log [A] = log 100 – 0.9207
log [A] = 2 – 0.9207
log[A] = 1.0973
[A] = antilog of (1.0973)
[A] = 12.5%
APPEARS IN
RELATED QUESTIONS
Write order of the following reaction:
\[\ce{2NH_{3(g)} -> N_{2(g)} + 3H_{2(g)}}\]
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?
The following reactions follow zero order kinetics, EXCEPT ____________.
How long would it take to electroplate a spoon with 0.1 mol of silver (108 g/mol) at a constant current of 2.0 A using AgNO3?
The rate constant of a reaction has same units as the rate of reaction. The reaction is of ____________.
Which among the following is an example of zero order reaction?
A first order reaction takes 40 minutes for 30% decomposition. What is the half-life of reaction?
A first order reaction is 50% completed in 16 minutes. The percentage of reactant that will react in 32 minutes is ____________.
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:
Which among the following reactions is an example of pseudo first order reaction?
