Answer
0.833 L of that solution contains 5.00 moles of $HCl$.
Work Step by Step
1. Since the molarity of that solution is equal to $ 6.00 \space M \space HCl$:
$1 \space L \space solution = 6.00 \space moles \space HCl$
$\frac{1 \space L \space solution}{ 6.00 \space moles \space HCl} $ and $\frac{ 6.00 \space moles \space HCl}{1 \space L \space solution}$
2. Use the conversion factors to calculate the volume of that solution that has 5.00 moles $HCl$:
$5.00 \space moles \space HCl \times \frac{1 \space L \space solution}{ 6.00 \space moles \space HCl} = 0.833 \space L \space solution$
