Abuffer is composed of nh3 and nh4cl. how would this buffer solution control the ph of a solution when a small amount of a strong base is added?

According to Le-chatelier principle, equilibrium will shift towards left to minimize concentration of and keep same equilibrium constant

Explanation:

In this buffer following equilibrium exists -

So, is involved in the above equilibrium.

When a strong base is added to this buffer, then concentration of increases. Hence, according to Le-chatelier principle, above equilibrium will shift towards left to minimize concentration of and keep same equilibrium constant.

Therefore excess amount of combines with to produce ammonia and water. So, effect of addition of strong base on pH of buffer gets minimized.