Answer :
ANSWER
The concentration of the base is 1.25M
EXPLANATION
Given that;
The volume of HCl is 25mL
The concentration of HCl is 1M
The volume of NaOH is 20mL
Follow the steps below to find the concentration of NaOH
Step 1; Write a balanced equation for the reaction
[tex]\text{ HCl}_{(aq)}\text{ }+\text{ NaOH}_{(aq)}\text{ }\rightarrow\text{ NaCl}_{(aq)}\text{ }+\text{ H}_2O_{(l)}[/tex]In the reaction above, 1 mole HCl reacts with 1 mole NaOH to gives 1 mole NaCl and 1 mole H2O
Step 2; Find the concentration of NaOH using the below formula
[tex]\text{ }\frac{\text{ CA VA}}{\text{ CB VB}}\text{ }=\frac{\text{ nA}}{\text{ nB}}[/tex]Where
CA is the concentration of the acid
VA is the volume of the acid
CB is the concentration of the base
VB is the volume of the base
nA is the number of moles of the acid
nB is the number of mole of the base
Recall, that HCl is the acid and NaOH is the base
Step 3; Substitute the given data into the formula in step 2
[tex]\begin{gathered} \text{ }\frac{\text{ 25 }\times\text{ 1}}{20\text{ }\times\text{ CB}}\text{ }=\frac{1}{1} \\ \\ \text{ }\frac{\text{ 25}}{\text{ 20CB}}\text{ }=\frac{1}{1} \\ \text{ cross multiply} \\ \text{ 25 }\times\text{ 1 }=\text{ 1 }\times\text{ 20CB} \\ \text{ 25 = 20CB} \\ \text{ Divide both sides by 20} \\ \frac{25}{20}\text{ = CB} \\ \text{ CB = 1.25M} \end{gathered}[/tex]Therefore, the concentration of the base is 1.25M
