English
Karnataka Board PUCPUC Science 2nd PUC Class 12

Calculate the half-life of a first order reaction from the rate constant given below: 200 s−1 - Chemistry

Advertisements
Advertisements

Question

Calculate the half-life of a first order reaction from the rate constant given below:

200 s−1

Numerical

Solution

`t_(1/2) = 0.693/k`

= `0.693/200` 

= 3.46 × 10 −3 s

shaalaa.com
  Is there an error in this question or solution?
Chapter 4: Chemical Kinetics - Exercises [Page 119]

APPEARS IN

NCERT Chemistry [English] Class 12
Chapter 4 Chemical Kinetics
Exercises | Q 13 | Page 119

RELATED QUESTIONS

The integrated rate equation for first order reaction is A → products


Derive the relation between half life and rate constant for a first order reaction


The rate constant for a first order reaction is 100 s–1. The time required for completion of 50% of reaction is _______.

(A) 0.0693 milliseconds

(B) 0.693 milliseconds

(C) 6.93 milliseconds

(D) 69.3 milliseconds


The experimental data for decomposition of N2O5

\[\ce{2N2O5 -> 4NO2 + O2}\] in gas phase at 318K are given below:

t/s 0 400 800 1200 1600 2000 2400 2800 3200
102 × [N2O5]/mol L−1 1.63 1.36 1.14 0.93 0.78 0.64 0.53 0.43 0.35
  1. Plot [N2O5] against t.
  2. Find the half-life period for the reaction.
  3. Draw a graph between log [N2O5] and t.
  4. What is the rate law?
  5. Calculate the rate constant.
  6. Calculate the half-life period from k and compare it with (ii).

During nuclear explosion, one of the products is 90Sr with half-life of 28.1 years. If 1μg of 90Sr was absorbed in the bones of a newly born baby instead of calcium, how much of it will remain after 10 years and 60 years if it is not lost metabolically.


Which among the following reactions is an example of a zero order reaction?

a) `H_(2(g)) + I_(2(g)) -> 2HI_(g)`

b) `2H_2O_(2(l)) -> 2H_2O_(l) + O_(2(g))`

c) `C_12H_22O_(11(aq)) + H_2O_(l) -> C_6H_12O_(6(aq)) + C_6H_12O_(6(aq))`

d) `2NH_(3g)`   `N(2g) + 3H_(2(g))`


The half-life period of zero order reaction A → product is given by

(a) `([A]_0)/k`

(b) `0.693/k`

(c) `[A]_0/(2k)`

(d) `(2[A]_0)/k`


For the first order reaction, half-life is equal to ____________.


Calculate half-life period of life order reaction whose rate constant is 200 sec–1


Which radioactive isotope would have the longer half-life 15O or 19O? (Given rate constants for 15O and 19O are 5.63 × 10–3 s–1 and k = 2.38 × 10–2 s–1 respectively.)


A first-order reaction takes 69.3 min for 50% completion. What is the time needed for 80% of the reaction to get completed? (Given: log 5 = 0.6990, log 8 = 0.9030, log 2 = 0.3010)


Observe the graph shown in figure and answer the following questions:


Write the relationship between k and t1/2 (half-life period)


The half-life of cobalt 60 is 5.26 years. The percentage activity remaining after 4 years is ______%.


The rate of a first order reaction is 0.04 mol litre-1 s-1 at 10 minutes and 0.03 mol litre-1 sec-1 at 20 minutes after initiation. The half-life of the reaction is ______ min.


A first order reaction takes 40 min for 30% decomposition. Calculate `"t"_(1/2)`.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×