Question

A chemist adds 0.50 mol acetic acid (CH3CO2H) to a solution. What else should be added to maximize the buffering effect?

Answer 1

0.50 moles of CH3COONa should be added

Step-by-step explanation:

A buffer is a solution containing a weak acid and its salt or a weak base and the corresponding salt. The purpose of adding a buffer to a solution is to maintain the pH of the solution.

pH is given by the Henderson-Hasselbalch equation.

For an acid buffer like (acetic acid/sodium acetate)

`pH = pKa + log([Salt])/([Acid])`

Similarly for a basic buffer (ammonia/ammonium nitrate):

`pOH = pKb + log([Salt])/([Base])`

where Ka and Kb are the acid and base dissociation constants.

Here, 0.50 mol acetic acid (CH3COOH) corresponds to an acid buffer. In order to maximize the buffering effect an equal amount of salt i.e. 0.50 moles of sodium acetate (CH3COONa) should be added

Answer 2

.50,mol sodium acetate (NaCH3CO2) should be added to maximize the buffering effect.

A buffering effect is a process in which a psychosocial resource reduces the impact of life stress on psychological well-being. Having such a resource contributes to adjustment because persons are less affected by negative life events.