Question

In experiments D-1 and D-3, hyhrochloric acid was added one drop at a time to a buffer solution and to deionized water. Did the buffer minimize changes in ph with each addition compared to water? If it did, explain in general terms how the buffer was able to do it.

Answer 1

A buffer is a solution containing a weak acid and its conjugate base (i.e. CH₃COOH and CH₃COO^-) or a weak base and its conjugate acid (i.e. NH₃ and NH₄⁺).

A buffer solution will keep relatively stable pH after addition of one drop of HCl solutions are added each time. In this the conjugate base of the buffer will get neutralize after adding the acid so there is no much change in the pH.

If the sam eamount of HCl solution was added to deionized water, the pH will change from neutral to acidic drastically. In this the H+ ions donates into water which increases the H+ ion concentration in the water inturn increases the acidic strength.