Question

20ml of 0.1 M HCL was reacted with 30ml of 0.2M naoh. The molarity of na+ ions in the solution ??

Answer 1

We begin by writing the equation of the reaction :

HCl (aq) + NaOH (aq) — > NaCl (aq) + H₂O (l)

The mole ratio is 1 : 1

The moles of HCl in 20 ml

20/1000 × 0.1 = 0.002 moles

The moles in 30 ml of NaOH is still 0.002 moles.

The molarity of sodium hydroxide is:

1000/30 × 0.002 = 0.067 M