Question

Question #6f712

Answer 1

`"0.118 L"`

Explanation:

To work out how many litres of sulfuric acid we need, we have to first work out the moles of sulfuric acid we have reacting in our equation.

`1.` Write a balanced equation:

(aluminium `+` sulfuric acid `rarr` aluminium sulfate + hydrogen)

`2"Al" + 3"H"_2"SO"_4 rarr "Al"_2("SO"_4)_3 + 3"H"_2`

`2.` Work out the moles of one reagent and use the molar ratio to work out the moles of the other:

moles of `"Al"` = `("mass")/"A"_"r"= 12.7/27.0 = 0.470`

molar ratio of `"Al":"H"_2"SO"_4` = `2:3`; `therefore`
moles of `"H"_2"SO"_4 = 0.470*(3/2) = 0.705`

`3.` Solve for the unknown:

We know that `"M" = "m"/"L"`, so we can now solve for `"L"`:

`6.00=0.705/"L"`

`"6.00 L"=0.705`

`"L"=0.705/6.00 = 0.118`