Question

A 59.0 mL portion of a 1.80 M solution is diluted to a total volume of 258 mL. A 129 mL portion of that solution is diluted by adding 183 mL of water. What is the final concentration

Answer 1

0.170 M

Step-by-step explanation:

As this is a series of dilutions, we can continuosly use the C₁V₁=C₂V₂ formula to solve this problem:

For the first step:

• 59.0 mL * 1.80 M = 258 mL * C₂

• C₂ = 0.412 M

Then for when 129 mL of that 0.412 M are diluted by adding 183 mL of water:

• V₂ = 129 mL + 183 mL = 312 mL

Using C₁V₁=C₂V₂:

• 129 mL * 0.412 M = 312 mL * C₂

• C₂ = 0.170 M