Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0011 % Pb by mass. How much of the water (in mL ) contains 165mg of Pb? (Assume a density of 1.0 g/ml.)

Question

Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0011 % Pb by mass. How much of the water (in mL ) contains 165mg of Pb? (Assume a density of 1.0 g/ml.)

Answer 1

Use proportions:

(165/1000) g / 0.0011%
=0.165 g/0.000011
=15,000 mL

Answer 2

But when you write it up to submit it please include the units so the equations balance!

Answer 3

To find out how much water (in mL) contains 165 mg of Pb, we need to use the information given about the percentage of Pb in the contaminated water sample, as well as the density of water.

First, let's calculate how much Pb is in the water sample. We are given that the water sample contains 0.0011% Pb by mass. This means that for every 100 g of the water sample, there is 0.0011 g of Pb.

To find the mass of Pb in the water sample, we can set up the following equation:

Mass of Pb = Percentage of Pb × Mass of Water Sample

Mass of Pb = 0.0011% × Mass of Water Sample

We know that the mass of Pb is 165 mg (given in the question), so we can write:

165 mg = 0.0011% × Mass of Water Sample

Next, we need to convert the mass of Pb to grams since the density of water is given in grams per milliliter. There are 1000 mg in 1 g, so:

Mass of Pb = 165 mg ÷ 1000 = 0.165 g

Now we can solve for the mass of the water sample:

0.165 g = 0.0011% × Mass of Water Sample

To isolate the Mass of Water Sample, divide both sides of the equation by 0.0011%:

Mass of Water Sample = 0.165 g ÷ (0.0011%)

To simplify the calculation, let's convert 0.0011% to decimal form. There are 100 parts in 1%, so:

0.0011% = 0.0011 ÷ 100 = 0.000011

Now we can substitute this value into the equation:

Mass of Water Sample = 0.165 g ÷ 0.000011

Mass of Water Sample ≈ 15,000 g (rounded to the nearest whole number)

Finally, we need to convert the mass of the water sample to volume, using the density of water. We are given that the density of water is 1.0 g/mL. Therefore:

Volume of Water Sample = Mass of Water Sample ÷ Density of Water

Volume of Water Sample ≈ 15,000 mL (rounded to the nearest whole number)

So, approximately 15,000 mL of water contains 165 mg of Pb.