The following data were obtained during | 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 21: . 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 21:

The following data were obtained during the first order thermal decomposition of SO2Cl2at a constant volume.

SO2Cl2(g)  →  SO2(g) + Cl2(g)

Experiment

Time/s - 1

Total pressure/atm
1 0 0.5
2 100 0.6

Calculate the rate of the reaction when total pressure is 0.65 atm.

Answer:

The thermal decomposition of SO2Cl2at a constant volume 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= 100 s,

k = 2.303 / 100s log 0.5 / 2x0.5 - 0.6

= 2.231 × 10 - 3s - 1

 

When Pt= 0.65 atm,

P0+ p= 0.65

⇒ p= 0.65 - P0

= 0.65 - 0.5

= 0.15 atm

Therefore, when the total pressure is 0.65 atm, pressure of SOCl2 is

pSOCL2 = P0 - p

= 0.5 - 0.15

= 0.35 atm

Therefore, the rate of equation, when total pressure is 0.65 atm, is given by,

Rate = k(pSOCL2)

= (2.23 × 10 - 3s - 1) (0.35 atm)

= 7.8 × 10 - 4atm 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.

Latest Blog Posts

Stay updated with our latest educational content and study tips

Why Self-Discipline is More Important Than Motivation for Students

Have you ever noticed that doing activities such as playing outdoors, chilling with your friends, or using the mobile phone feels so effortless and fun? Whenever you might have played sports, you kept on playing even when it felt hard initially just so you could get that feeling after the game, a feeling of accomplishment, … Read more

Read More

How Visualization Strategies Can Improve Test Performance

Imagine this; You’re sitting in the test hall, pen in hand, and the question paper has been put in front of you. Rather than freezing, you feel calm, collected, and set. Why? As you have formerly been there in your mind. You’ve seen yourself sitting composibly, reviewing the question paper fluently, performing well in the … Read more

Read More

Smart Questions to Ask in a Parent-Teacher Meeting | PTM Made Easy

Parent-Teacher Meetings (PTMs) are more than quick updates on marks — they’re a chance to build a real partnership between home and school. A good Parent-Teacher Meeting conversation helps parents see beyond grades. It opens up insights about a child’s strengths, struggles, emotions and even hidden talents. When parents participate actively, they don’t just track … Read more

Read More

The Secret to Smarter Learning — Building Strong Critical Thinking Skills

In today’s world of endless information , knowing how to think is more important than knowing what to think . From school projects to real – life decisions , critical thinking helps students question ideas , analyze facts and form logical conclusions . But what exactly does critical thinking mean ? Simply put , it’s … Read more

Read More

Comments

  • Kishore
  • Mar 10, 2019

Yes! i got the answer thanks


  • Aynal Hoque
  • Oct 23, 2018

Yup,I got it thanks


  • Ram S Kaushik
  • Dec 25, 2017

Thanks for the solution.It was very useful.


Add Comment

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 21: The following data were obtained during the first order thermal decomposition of SO2Cl2at a constant....