Question

The half-life period of a first order reaction is 100
minute. Calculate the time required for the reaction
to be completed by 90%.
min​

Answer 1

Answer:

339.32 sec

Explanation:

Half  life time ( t1/2)   = 100 sec. (given)  

K= 0.693/ 100    

Time required for 90% completion?  

Here let initial concentration =a  

Concentration decomposed is 90%  

x= 90×a/ 100

   =0.9a  

Now,  

t= 2.303  /0.693/(t1/2) log  (a/a−x)

⇒2.303/100 log (a/ a−0.9a)

⇒ 2.303/0.693 log (a/0.1a)

⇒2.303/100 log 10

⇒2.303/0.693 x 100 x log 10

⇒339.32 sec.

​ HOPE IT HELPS :)....

                     

 

 

 

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