# What is the concentration in parts per million of a 500 g sample of drinking water that contains 45 mg of lead?

Feb 14, 2018

$\text{90 ppm}$

#### Explanation:

PPM can be better understood in typical units of concentration!

PPM can also be represented as mg/L!

Assuming the density of water is 1.0g/ml, we can translate 500.0g of water to be 500.0mL of water!

Therefore,

Turning 500.0mL of water into L first;

$\text{500 mL" * "1 L"/"1000 mL" = "0.5 L}$

For PPM, we want to keep our mass in mg, which was already supplied!

As such,

$\text{45 mg" /"0.5 L" = "90 mg/L" = "90 ppm}$