Chem5
posted by Ryan .
A dioxincontaminated water source contains 0.052% dioxin by mass. How much dioxin (in g) is present in 4.2 liters of this water? (Assume the solution density is 1.00 g/mL.)

recall that density is mass over volume, or
d = m/V
substituting,
1 = m / 4200
m = 4200 g H2O
to get the mass of dioxin, we just multiply its percent mass:
4200 * 0.00052 = 2.184 g dioxin
hope this helps~ :)