Question

How many grams of hydrogen are in one mole of sulphuric acid?

Answer 1

`"2.016 g"`

Explanation:

Start by taking a look at the chemical formula of sulfuric acid,

`"H"_2"SO"_4`

Notice that you have two hydrogen atoms per formula unit of sulfuric acid.

This means that one mole of sulfuric acid will contain 2 moles of hydrogen atoms.

The molar mass of sulfuric acid is `"98.0795 g/mol"`. This means that every mole of sulfuric acid has a mass of `"98.0795 g"`.

Since you're dealing with one mole of sulfuric acid, it follows that you will also be dealing with two moles of hydrogen. Use hydrogen's molar mass to determine how many grams would contain this many moles

`2color(red)(cancel(color(black)("moles H"))) * "1.00794 g"/(1color(red)(cancel(color(black)("mole H")))) = "2.016 g H"`

You will need to round this off to the number of sig figs you are given for the number of moles of sulfuric acid. If you have `1` mole, the answer will be

`m_"H" = "2 g" ->` rounded to one sig fig

If you have `1.0` moles of sulfuric acid, you get

`m_"H" = "2.0 g" ->` rounded to two sig figs;

And so on.