Question

A 25.0 ml sample of an unknown hbr solution is titrated with 0.100 m naoh. the equivalence point is reached upon the addition of 18.88 ml of the base. what is the concentration of the hbr solution?

Answer 1

1) Neutralization equation:

HBr + NaOH --> NaBr + H2O

2) 1: 1 molar ratio => 1 mol NaOH neutralizez 1 mol HBr

3) M = n / V => n = M*V

=> M*V for NaOH = M*V for HBr

0.01888 l * 0.100M = x * 0.025 l =>  0.01888 l * 0.10 M / 0.025 l = 0.0755 M

Answer: 0.0755 M