In: Chemistry
Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0010 % Pb by mass
How much of the water (in mL) contains 145 mg of Pb? (Assume a density of 1.0 g/mL.) Express your answer using two significant figures.
0.001% means 0.001 g of Pb in 100g of H2O
1 g of Pb present in (100/0.001 )*1 = 10^5 g of H2O
145 mg of Pb present in 10^5 * 145 * 10^-3 g
= 14500 g of water
= 1.45 * 10^4 g of H2O
since density = 1 g /mL then
= 1.4 * 10^4 mL of H2O (2 significants)