Question

How many grams of `H_3PO_4` are in 175 mL of a 3.5 M solution of `H_3PO_4`?

Answer 1

Around `60` grams.

Explanation:

We have a `3.5 \ "M"` solution of phosphoric acid with `175 \ "mL` of it in there. This means that there are:

`(3.5 \ "mol")/(color(red)cancelcolor(black)"L")*0.175color(red)cancelcolor(black)"L"=0.6125 \ "mol"`

So, there exist `0.6125` moles of phosphoric acid here.

Phosphoric acid has a molar mass of `97.994 \ "g/mol"`.

So here, the mass is:

`0.6125color(red)cancelcolor(black)"mol"*(97.994 \ "g")/(color(red)cancelcolor(black)"mol")~~60 \ "g"`