Answer
480. mL of that solution contains 1.20 moles of $K_2SO_4$.
Work Step by Step
1. Since the molarity of that solution is equal to $ 2.50 \space M \space K_2SO_4$:
$1 \space L \space solution = 2.50 \space moles \space K_2SO_4$
$\frac{1 \space L \space solution}{ 2.50 \space moles \space K_2SO_4} $ and $\frac{ 2.50 \space moles \space K_2SO_4}{1 \space L \space solution}$
2. To convert from milliliters to liters: 1 L = 1000 mL
$\frac{1 \space L}{1000 \space mL}$ and $\frac{1000 \space mL}{1 \space L}$
3. Use the conversion factors to calculate the volume of that solution that has 1.20 moles $K_2SO_4$:
$1.20 \space moles \space K_2SO_4 \times \frac{1 \space L \space solution}{ 2.50 \space moles \space K_2SO_4} \times \frac{1000 \space mL}{1 \space L} = 480. \space mL \space solution$
