Problem: Two 20.0mL samples, one 0.100 M HCl and the other 0.100 M HF, were titrated with 0.200 M KOH. Answer each of the following questions regarding these two titrations.Part AWhat is the volume of added base at the equivalence point for HCl?Part BWhat is the volume of added base at the equivalence point for HF?Part CPredict whether the pH at the equivalence point for each titration will be acidic, basic, or neutral.Part DPredict which titration curve will have the lowest initial pH.

FREE Expert Solution

We are asked to answer each of the following questions regarding these two titrations.

Part A

At the equivalence point, moles of acid = moles of base. 

We use the equation below to calculate volume: 

$$\begin{gathered} \boxed{{\mathbf{\left(}\mathbf{MV}\mathbf{\right)}}_{\mathbf{a}}\mathbf{ }\mathbf{=}\mathbf{ }{\mathbf{\left(}\mathbf{MV}\mathbf{\right)}}_{\mathbf{b}}} \\ \mathbf{(}\mathbf{0}\mathbf{.}\mathbf{100}\mathbf{ }\mathbf{M}\mathbf{)}\mathbf{(}\mathbf{20}\mathbf{ }\mathbf{mL}\mathbf{)}\mathbf{ }\mathbf{=}\mathbf{ }\mathbf{(}\mathbf{0}\mathbf{.}\mathbf{200}\mathbf{ }\mathbf{M}\mathbf{)}\mathbf{\left(}{\mathbf{V}}_{\mathbf{b}}\mathbf{\right)} \\ {\mathbf{V}}_{\mathbf{b}}\mathbf{ }\mathbf{=}\mathbf{ }\frac{\mathbf{(}\mathbf{0}\mathbf{.}\mathbf{100}\mathbf{ }\cancel{\mathbf{M}}\mathbf{)}\mathbf{(}\mathbf{20}\mathbf{ }\mathbf{mL}\mathbf{)}\mathbf{ }}{\mathbf{(}\mathbf{0}\mathbf{.}\mathbf{200}\mathbf{ }\cancel{\mathbf{M}}\mathbf{)}} \end{gathered}$$

V_b = 10 mL KOH

10 mL 0.200 M KOH will be needed to titrate 20 mL 0.100 M HCl 

Part B

At the equivalence point, moles of acid = moles of base. 

We use the equation below to calculate volume: