Question

How do I calculate the volume needed of .100 M KOH to completely neutralise the HCl in 300mL of hydrochloric acid solution that has a pH of 2.25. I have the answer as this was a practice question but want to know how to calculate this

Answer 1

Answer:

Molatrity of acid = Ma = 0.1

Volume of acid = Va = 20mL = 0.02L

No. of molecules of acid = Na = n (according to balanced chemical equation for every mole of HCl, one mole of Naoh is needed)

Molarity of base = Mb = ?

Volume of base = Vb = 300mL= 0.300L

No. of molecules of base = Nb = n (according to balanced chemical equation for every mole of HCl , one mole of Naoh is needed)

By simplifying the equation we get:

Ma x Va = Mb x Vb

Mb= (Ma x Va) ÷ Vb

Mb= (0.1 x 0.02) ÷ 0.300

Mb=0.00666666666