Answer
mass=564 grams
Work Step by Step
This question is, in essence, a density problem. We are given a density and a displaced volume, and we have to find the mass. The density is 4.51 g/$cm^{3}$, and the volume displaced is 125.0 mL. Since one mL=one $cm^{3}$, the volume displaced is 125 $cm^{3}$. When we substitute in our values into the density formula (density=mass/volume), and solve for mass, we get a mass of 564 grams.