Solutions that resist changes in pH are called .

A buffer is a solution that resists changes in pH upon the addition of a small amount of strong acid or strong base. Technical definition (How do you make one?): A buffer is composed of a mixture·of a weak acid its conjugate base.

Explanation:

Paraldehyde is produced for commerce by polymerizing acetaldehyde with a trace of sulfuric acid; the resulting liquid is then neutralized with calcium carbonate and purified by fractional distillation. Paraldehyde boils at 124° C (255° F) and melts at a temperature of 12.5° C (54.5° F).