Question

Are `"magnesium phosphate/magnesium bromide"`, `"sulfuric acid/sodium bisulfate"` `"buffer solutions"`?

Answer 1

`MgBr_2"/"MgHPO_4; H_2SO_4"/"NaHSO_4` are NOT buffer systems.

Explanation:

A buffer solution is composed of a weak acid and its conjugate base in APPRECIABLE concentrations, which acts to keep `pH` close to the `pK_a` of the weak acid, and resist gross changes in `pH`. Both sulfuric acid and sodium bisulfate are strong acids in water, and thus do not fall under the umbrella of the given definition.

The `pK_a` of lactic acid would be similar to that of acetic acid (says he, without bothering to look up the `pK_a` of lactic acid; it would be reasonably close to `4.76`), and hence this system COULD act as a buffer.

All of this presupposes AQUEOUS solution.