A 2.0 mL sample of NaOH solution is exactly neutralized by 4.0 mL of 3.0 M HCl solution. What is the concentration of the NaOH solution?

1 Answer
Jun 3, 2016

[NaOH] = 6.0molL1

Explanation:

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

Clearly a 1:1 stoichiometry pertains. We know the concentration of the hydrochloric acid, and we use this to calculate (i) the number of moles of hydrochloric acid, and (ii) the concentration of the caustic soda.

Moles of hydrochloric acid = 4.0×103L×3.0molL1 = 12×103mol

Concentration of sodium hydroxide = Moles of NaOHInitial volume of solution = 12×103mol2.0×103L