Question

Calculate the final concentration of each of the following diluted solutions:

A) 0.50 L of a 4.0 M HNO3 solution is added to water so that the final volume is 8.0 L

B) Water is added to 0.55 L of a 6.0 M KOH solution to make 2.0 L of a diluted KOH solution.

C) A 35.0 mL sample of 8.0 % (m/v) NaOH is diluted with water so that the final volume is 200.0 mL.

D) A 8.0 mL sample of 50.0 % (m/v) acetic acid (HC2H3O2) solution is added to water to give a final volume of 25 mL .

Answer 1

(A) According to law of dilution   MV = M'V'

Where M = Molarity of stock = 4.0M

V = Volume of the stock = 0.50 L

M' = Molarity of dilute solution = ?

V' = Volume of the dilute solution = 8.0 L

Plug the values we get   , M' = MV /V' = 0.25 M

(B) According to law of dilution   MV = M'V'

Where M = Molarity of stock = 6.0M

V = Volume of the stock = 0.55 L

M' = Molarity of dilute solution = ?

V' = Volume of the dilute solution = 2.0 L

Plug the values we get   , M' = MV /V' = 1.65 M

(C) According to law of dilution   MV = M'V'

Where M = Molarity of stock = 8.0 %(m/V)

V = Volume of the stock = 35 mL

M' = Molarity of dilute solution = ?

V' = Volume of the dilute solution = 200.0 mL

Plug the values we get   , M' = MV /V' = 1.4 % (m/v)

(D) According to law of dilution   MV = M'V'

Where M = Molarity of stock = 50.0 %(m/v0

V = Volume of the stock = 8.0 mL

M' = Molarity of dilute solution = ?

V' = Volume of the dilute solution = 25 mL

Plug the values we get   , M' = MV /V' = 16 %(m/v)