Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are false
- Both Statement I and Statement II are true
- Statement I is false but Statement II is true
- Statement I is true but Statement II is false
Answer
(3) Statement I is false but Statement II is true
Solution
A buffer is a weak acid + its salt with a strong base (e.g. CH3COOH/CH3COONa) or a weak base + its salt with a strong acid (e.g. NH4OH/NH4Cl), taken in a suitable ratio.
Since any salt with any acid or base in any quantity need not resist a change of pH, Statement I is false.
Blood is buffered by H2CO3 (weak acid) and HCO3- (its conjugate base), which keep its pH near 7.4, so Statement II is true.
Answer: (3)