Question

Identify the final concentrations of each species following the addition of 1.0 M KOH to a 2.0 M HF solution. HF(aq) + KOH(aq) + KF(aq) + H2O(1) initial 2.0 M 1.0M OM change final ? ? [HF] = (KOH) = (KF) = Which best describes the final solution? O a neutral salt solution O a buffer O Neither describes the final solution.

Answer 1

Above problem is acid base neutralisation. KOH behaves as limiting reagent. Hence KOH will react with HF completely.

After the complete reaction KOH will react completely. So the change in every species will 1.0 M

So final concentration of species are as follows:

1. [HF] = 2.0 - 1.0 = 1.0 M

2. [KOH] = 1.0 - 1.0 = 0.0 M

3. [KF] = 0.0 + 1.0 = 1.0 M

In the final solution only HF and KF is present i.e. HF is weak acid and KF is it's salt.

Hence the final solution behaves as buffer solution.

Ans = buffer.