what is the molar concentration.

Question

Stomach acid" is hydrochloric acid. A sample of gastric juice having a volume of 4.67 mL required 18.93 mL of 0.0131 M KOH solution for neutralization in a titration. What was the molar concentration of HCl in this fluid?

C(HCl) =  

If we assume a density of 1.00 g mL^-1 for the fluid, what was the percentage by weight of HCl?

w(HCl) = 

Answer 1

The reaction taking place is

HCl + KOH ==> KCl + H2O neutralization reaction

1 mole of HCl is neutralized by 1 mole of KOH

1. Find the moles of KOH used: 18.93 ml x 1 L/1000 ml x 0.0131 mol/L = 0.00024798 moles KOH
2. Moles of HCl present = 0.00024798 mol KOH x 1 mol HCl/mol KOH = 0.00024798 moles HCl
3. Molar concentration of HCl = 0.00024798/0.00467 L = 0.0531 moles/L = 0.0531 M (to 3 sig. figs.)