buffer solution is comprised of 0.10 M NH3 and 0.10 M NHCI. A small volume of NaOH is added to the solution. Select all the spectator ions.

Question

A) H30+

b.) Cl-

C.)NH4^+

D.) Na^+

Answer 1

First, you have typo, and the solution should contain 0.10 M NH₃ and 0.10 M NH₄Cl.

Now, let's look at the reactions taking place when a small volume of NaOH is added. This is a buffer and so the added NaOH being a base will react with the acid present (NH₄Cl).

NaOH(aq) + NH₄Cl(aq) ==> NaCl(aq) + NH₄OH(aq) .. molecular equation

Na⁺(aq) + OH^-(aq) + NH4⁺(aq) + Cl^-(aq) ==> Na⁺(aq) + Cl^-(aq) + NH₄OH(aq) .. ionic equation

NH4⁺(aq) + OH^-(aq) ==> NH₄OH(aq) .. net ionic

So, in this reaction the spectator ions are Na⁺ and Cl^-

H₂O + H₂O ==> H₃O⁺ + OH^-

In this reaction, the spectator ion is H₃O⁺