Question

Which may be added to one litre of water to act a buffer?
A. One mole of `CH_(3)COOH` and one mole of `HCl`
B. One mole of `NH_(4)OH` and one mole of `NaOH`
C. One mole of `NH_(4)Cl` and one mole of `HCl`
D. One mole of `CH_(3)COOH` and `0.5` mole of `NaOH`

Answer 1

Correct Answer - D
`underset(0.5)underset(1)(HC_(2)H_(3)O_(2))+underset(0)underset(0.5)(NaOH) rarr underset(0.5)underset(0)(C_(2)H_(3)O_(2)Na)+underset(0.5)underset(0)(H_(2)O)`
This solution contains weak acid `+` its salt with strong base and thus acts as buffer.