If you add 25.0 mL of water to 125 mL of a 0.150 M LiOH solution, what will be the molarity of the resulting diluted solution?

0.0450 M LiOH

0.0647 M LiOH

0.125 M LiOH

0.134 M LiOH

Concentration is the number of moles of solute in a fixed volume of solution

Concentration (c) = number of moles of solute (n) / volume of solution (v)

25.0 mL of water is added to 125 mL of a 0.150 M LiOH solution and solution becomes more diluted.

original solution molarity - 0.150 M

number of moles of LiOH in 1 L - 0.150 mol

number of LiOH moles in 0.125 L - 0.150 mol / L x 0.125 L = 0.01875 mol

when 25.0 mL is added the number of moles of LiOH will remain constant but volume of the solution increases

new volume - 125 mL + 25 mL = 150 mL

therefore new molarity is

c = 0.01875 mol / 0.150 L = 0.125 M

answer is 0.125 M