Question
Chemistry Question on Structure of atom
When 10ml of 0.2M solution of an acid is added to 250ml of a buffer solution with pH=6.34, the pH of the solution becomes 6.32. The buffer capacity of the solution is:
A
(A) 0.1
B
(B) 0.2
C
(C) 0.3
D
(D) 0.4
Answer
(D) 0.4
Explanation
Solution
Explanation:
The expression for the buffer capacity is as follows:Buffer capacity = Number of moles of acid or base added per litre Change in pH10ml of 0.2M acid is added to 250ml of a buffer solution. Number of moles of acid added =0.2×101000Therefore, the number of moles of acid added per litre, =0.2×101000×1000250=0.008Change in pH=6.34−6.32=0.02Substituting values in the above expression, we get,Buffer capacity =0.0080.02=0.4Therefore, the buffer capacity is 0.4.Hence, the correct option is (D).