For the decomposition of azoisopropane t | Class 12 Chemistry Chapter Chemical Kinetics, Chemical Kinetics NCERT Solutions

Welcome to the NCERT Solutions for Class 12 Chemistry - Chapter Chemical Kinetics. This page offers a step-by-step solution to the specific question from Exercise 2, Question 20: . With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 20:

For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data are obtained.

t (sec) P(mm of Hg)
0 35.0
360 54.0
720 63.0

Calculate the rate constant

Answer:

The decomposition of azoisopropane to hexane and nitrogen at 543 K is represented by the following equation.

After time, t, total pressure, Pt = (Pº - p) + p + p

⇒ Pt = (Pº + p)

p = P - Pº

therefore, Pº - p = Pº  - P - Pº

= 2 Pº -  Pt

For a first order reaction,

k = 2.303/ Log  Pº / Pº  - p

=   2.303/ Log  Pº / 2 Pº  -  Pt

When t = 360 s, k = 2.303 / 360s log 35.0 / 2x35.0 - 54.0

= 2.175 × 10 - 3 s - 1

When t = 720 s, k = 2.303 / 720s log 35.0 / 2x35.0 - 63.0

= 2.235 × 10 - 3 s - 1

Hence, the average value of rate constant is

k = (2.175 × 10 - 3  + 2.235 × 10 - 3 ) / 2   s - 1

= 2.21 × 10 - 3 s - 1


Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

  • Read the question carefully and focus on the core concept being asked.
  • Reference examples and data from the chapter when answering questions about Chemical Kinetics.
  • Review previous year question papers to get an idea of how such questions may be framed in exams.
  • Practice answering questions within the time limit to improve your speed and accuracy.
  • Discuss your answers with your teachers or peers to get feedback and improve your understanding.

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Comments

  • Gnkp
  • Nov 17, 2019

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  • Jishan
  • Aug 17, 2019

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  • Stuti
  • Jul 01, 2019

Thankyou !! Helped alot!!


  • Ayush
  • Jun 07, 2019

Thnx alot


  • Subhadeep Raj
  • Mar 06, 2019

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  • Agrima
  • Jan 27, 2019

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  • Janhavi khalatkar
  • Nov 12, 2018

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  • Somya
  • Sep 25, 2018

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  • Arnav Shivam
  • Jul 26, 2018

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  • Jun 16, 2018

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Welcome to the NCERT Solutions for Class 12 Chemistry - Chapter . This page offers a step-by-step solution to the specific question from Excercise 2 , Question 20: For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data are obtai....