Question

If 3.00 mL of 0.0250 M CuSO4 is diluted to 25.0 mL with pure water, what is the molarity of copper(II) sulfate in the diluted solution

Answer 1

0.00268 M

Step-by-step explanation:

To find the new molarity, you need to (1) find the moles of CuSO₄ (via the molarity equation using the beginning molarity and volume) and then (2) find the new molarity (using the moles and combined volume). Your final answer should have 3 sig figs to match the given values.

Step 1:

3.00 mL / 1,000 = 0.00300 L

Molarity = moles / volume (L)

0.0250 M = moles / 0.00300 L

(0.0250 M) x (0.00300 L) = moles

7.50 x 10⁻⁵ = moles

Step 2:

25.0 mL / 1,000 = 0.0250 L

0.0250 L + 0.00300 L = 0.0280 L

Molarity = moles / volume (L)

Molarity = (7.50 x 10⁻⁵ moles) / (0.0280 L)

Molarity = 0.00268 M