Final answer:
To calculate the number of moles of Cu²⁺ in 0.400 L of a 0.300 M CuSO₄ solution, multiply the molarity by the volume to get 0.120 moles.
Step-by-step explanation:
To calculate the number of moles of Cu2+ in 400.0 mL (or 0.400 L) of 0.300 M CuSO4 solution, we use the molarity formula:
Molarity (M) = Moles of solute (n) / Volume of solution in liters (L)
First, rearrange the molarity formula to solve for moles:
Moles of solute (n) = Molarity (M) × Volume of solution in liters (L)
Next, plug in the given molarity and volume:
n(Cu2+) = 0.300 M × 0.400 L
n(Cu2+) = 0.120 moles
The correct answer is (b) 0.120 moles of Cu2+.