Question

Bottled mineral water contains 25ppm calcium. How many milligrams of Ca does one take when one drinks 500.0 mL of bottled mineral water?

Answer 1

I get `12.5` milligrams of calcium.

Explanation:

The first thing to know is that `1 \ "ppm"=1 \ "mg/L"`. Click here for the explanation.

And so, `25 \ "ppm"=25 \ "mg/L"`.

Observe that `500 \ "mL"=500color(red)cancelcolor(black)"mL"*(1 \ "L")/(1000color(red)cancelcolor(black)"mL")=0.5 \ "L"`.

Therefore, you'll take:

`(25 \ "mg")/(color(red)cancelcolor(black)"L")*0.5color(red)cancelcolor(black)"L"=12.5 \ "mg"`

of calcium if you drink half a liter of bottled water.