Extra 416 C₁V₁ = C₂V₂ problems

1

In the laboratory, there are 4 L of HCl with a concentration of 1.0 g/L. Using this concentrated acid, you must prepare a 500 mL solution of HCl with a 0.01g/L.

Explain how you would prepare this solution.

SHOW YOUR WORK.

C₁V₁ = C₂V₂

1V₁= 0.01 (0.500)

V₁ = 0.0050 L

Pipet 0.005 L from the original 1.0 g/L.

Transfer to a 500 ml flask.

Add water to white line and mix.

2

Using 300 mL of a 2.0 g/L solution of copper sulfate, CuSO₄, a student must prepare a 0.50 g/L solution of copper sulfate.

What volume of H₂O must be added to prepare the 0.50 g/L solution?

Show all your work.

C₁V₁ = C₂V₂

2(0.300) = 0.50 V₂

2(0.300)/ 0.50 = V₂

1.2 L = V₂

So we need to add 1.2 – 0.3 = 0.9 L

3

You are given 60 mL of a 45 g/L aqueous solution and asked to dilute it to obtain a concentration of 30 g/L.

What is the volume of the resulting solution?

A)	22.5 mL	C)	90 mL
B)	40 mL	D)	105 mL

C₁V₁ = C₂V₂

45(0.060) = 30V₂

V₂ = 0.090 L

Answer (C) = 90 ml

4

A beaker contains 200 mL of a 60 g/L solution. A student added 400 mL of water to this solution.

What is the concentration of the diluted solution?

C₁V₁ = C₂V₂

60(0.200) = C₂(0.200 + 0.400)

12/(0.60) = 20 g/L