Class 10
Chapter 2 Class 10 - Acids, Bases and Salts

Assertion (A): To dilute sulphuric acid, acid is  added to water and not water to acid.  

Reason (R): Specific heat of water is quite large.  

 

Directions: In the following questions, a statement  of assertion (A) is followed by a statement of  reason (R). Mark the correct choice as:  

(a) Both assertion (A) and reason (R) are true and  reason (R) is the correct explanation of assertion  (A).  

(b) Both assertion (A) and reason (R) are true but  reason (R) is not the correct explanation of  assertion (A).  (c) Assertion (A) is true but reason (R) is false.  

(d) Assertion (A) is false but reason (R) is true.  

 

Answer 

Add acids to water and not water to acid-Teachoo.jpg

Now,

  • The mixing of water to an acid is  highly exothermic in nature. 
  • If water is added to an  acid it produces a very large amount of heat. This  can break the container and sometimes even causes burning as acids can heat up very quickly. 
  • So it is advised to add concentrated acid  to water in a very slow manner.  

 

Also,

  • Specific heat capacity is the amount of heat needed to raise one gram of a material by one degree celsius.
  • Specific heat of water is high as compared to other materials

 

Since the specific heat of water is high , it takes a lot of heat to increase its temperature. Thus, we add acid to water and not water to acid

 

Thus,

  • Assertion is true
  • Reasoning is true
  • And Reasoning is the correct explanation of Assertion

So, the correct answer is (a)

Ask a doubt
Maninder Singh's photo - Co-founder, Teachoo

Made by

Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo