Answer
The final volume must be equal to 6.0 L.
Work Step by Step
1. Using the equation: $M_1V_1 = M_2V_2$
$$\frac{M_1V_1}{M_2} = V_2$$
$$V_2 = \frac{( 12 \space M)( 50.0 \space mL )}{ 0.100 \space M} = 6.0 \times 10^{3} \space mL = 6.0 \space L$$
