Home
Class 12
CHEMISTRY
A first order reaction is 50% completed ...

A first order reaction is 50% completed in 40 minutes at 300 K and in 20 minutes at 320 K. Calculate the activation energy of the reaction.
[Given : `log 2=0.3010, log 4=0.6021, R=8.314 JK^(-1)"mol"^(-1)`]

Text Solution

Verified by Experts

For a first order reaction
`k=(2.303)/(t)"log"([R]_(0))/([R])`
At 300K
`k_(1)=(2.303)/(40)"log"([R]_(0))/([R]_(0)//2)=(2.303)/(40)"log 2"=(2.303)/(40)xx0.3010`
AT 320 K
`k_(2)=(2.303)/(20)"log"([R]_(0))/([R]_(0)//2)=(2.303)/(20)log2=(2.303)/(20) xx 0.3010`
`(k_(2))/(k_(1))=(2.303xx0.3010xx40)/(20xx2.303xx0.3010) =2`
Applying Arrhenius equation, we have
`"log"(k_(2))/(k_(1))=(E_(a))/(2.303R)[(T_(2)-T_(1))/(T_(1)T_(2))]`
Substituting the values, we have
`log 2=(E_(a))/(2.303xx8.314JK^(-1)"mol"^(-1))[(320K-300K)/(320K xx 300K)]`
or `0.3010=(E_(a))/(19.1471)[(20)/(96000)]`
or `E_(a)=(0.3010xx19.1471xx96000)/(20)=27663.7J`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • CHEMICAL KINETICS

    U-LIKE SERIES|Exercise LONG ANSWER QUESTIONS-II |13 Videos

  • CHEMICAL KINETICS

    U-LIKE SERIES|Exercise SELF ASSESSMENT TEST (SECTION A) (MULTIPLE CHOICE QUESTIONS) |7 Videos

  • CHEMICAL KINETICS

    U-LIKE SERIES|Exercise SHORT ANSWER QUESTIONS|41 Videos

  • CBSE EXAMINATION PAPER 2020 (CODE No.56/4/1)

    U-LIKE SERIES|Exercise SECTION -D|3 Videos

  • CHEMISTRY IN EVERYDAY LIFE

    U-LIKE SERIES|Exercise LONG ANSWER QUESTIONS - I|21 Videos

Similar Questions

Explore conceptually related problems

A first order reaction is 50% completed in 40 minutes at 300 K and in 20 minutes at 320 K. Calculate the activation energy of the reaction . (Given : log 2 = 0.3010 , log 4 = 0.6021 , R = 8.314 J K^(-1) mol^(-1) ) .

A first order reaction is 50% complete in 40 minutes at 300 K and in 20 minutes at 320 K. Calculate the activation energy of the reaction (Given: log 2 = 0.3010. log 4 = 0.6021, R = 8.314 JK^–1 mol^–1 )

Knowledge Check

  • A first order reaction is 50% completed in 30 minutes at 27^(@) and in 10 minutes at 47^(@)C . The energy of activation of the reaction is

    A
    42.84kJ `//`mol
    B
    34.84 KJ` //` mol
    C
    84.00 KJ `//` mol
    D
    30.00 KJ` //`mol

  • A first order reaction is 50% completed in 20 minutes at 27^(@) C and in 5 minutes at 47^(@) . The energy of activation of the reaction is :

    A
    43.85 KJ/mol
    B
    55.14 KJ/mol
    C
    11.97 KJ/mol
    D
    6.65 KJ/mol

  • A first order reaction is 50% completed in 20 minutes at 27^(@)C and in 5 min at 47^(@)C . The energy of activation of the reaction is

    A
    43.85 kJ/mol
    B
    55.14 kJ/mol
    C
    11.97 kJ/mol
    D
    6.65 kJ/mol

    • Similar Questions

    Explore conceptually related problems

    A first order reaction is 50% complete in 30 minutes at 27^@C and in 10 minutes at 47^@C . The energy of activation of the reaction is

    A first order reaction is 50% complete in 20 minutes. What is its rate constant?

    A first order reaction is 50% complete in 50 minutres at 300K and the same reaction is again 50% complete in 25 minutes at 350K . Calculate activation energy of the reaction .

    A first order reaction is 50% complete in 25 minutes at 350 K. Calculate activation energy of the reaction.

    At 100 K, a reaction is 30% complete in 10 minutes, while at 200 K, 30% is complete in 5 minutes . The activation energy of the reaction is :

    Home
    Profile