Question

You have 10.5 g of LiOH and want to make a 1.30 M LiOH solution, what volume of solution can be made?

10. If you dilute 45 mL of a 3.6 M H2SO4 solution to a final volume of 175mL, what is the new concentration of H2SO4?

Answer 1

1.     Given, mass of LiOH = 10.5g; Molarity of solution = 1.30M, Volume of solution = ?

Molar mass of LiOH = 24

now, moles of LiOH = 10.5/24 = 0.44

from relation, Molarity = moles of solute x 1000 / volume of solution

or volume of solution = moles of solute x 1000 / Molarity

volume of solution = 0.44 x 1000 / 1.30

volume of solution = 338.5mL

2. Given, C1 = 3.6M, V1 = 45mL, C2 = ? and V2 = 175mL

from relation, C1V1 = C2V2

C2 = C1V1 / V2

C2 = 3.6 x 45 / 175

C2 = 0.925M