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 150 mg of Pb? (Assume a density of 1.0 g>mL.)

Video transcript

Hey everyone, we're told that silicon dioxide, commonly known as silica can cause detrimental effects in water treatment operations when accumulated a sample of silicon dioxide contaminated water contains 0.250% of silicon dioxide by mass assuming a 1.0 g per milliliter density determine the volume of the sample in milliliters containing 325 mg of silicon dioxide. So first let's go ahead and take a look at our percent of silicon dioxide by mass that was given to us, which was said to be 0.0 to 50%. Now we can go ahead and change this into grams by assuming that we have 100 g of our solution. So this will in turn become 0.0 to g of silicon dioxide per grams of solution. Now to determine the volume of our sample, we're going to go ahead and use dimensional analysis Starting with our 325 mg of our silicon dioxide. We're first going to convert our milligrams into grams and we know that we have 10 to the third milligrams per one g. Next we're going to take that value of 0.00-50 g of silicon dioxide per 100 grams of solution. And we want to convert this grams of solution into milliliters and we can do so by taking our density. So we know that we have 1.00 g per one millimeter. So when we calculate this out and cancel out all of our units, We end up with a volume of 1.3 times 10 to the four ml, which is going to be our final answer. Now, I hope this made sense and let us know if you have any questions.