Question

If 30.2 g of aluminum react with HCI to produce aluminum chloride and hydrogen gas, how many liters of hydrogen are produced at STP?

Answer 1

Under `40*L` of dihydrogen gas are generated.

Explanation:

We must use a stoichiometric equation:

`Al(s) + 3HCl(aq) rarr AlCl_3(aq) +3/2H_2(g)uarr`

This equation tells us that `26.98*g` aluminum metal gives us `33.6*L` of dihydrogen gas. Why? Because `1` `mol` of gas occupies `22.4*L` at `"STP"` and `1.5*mol` were generated.

`"Moles of aluminum"` `=` `(30.2*g)/(26.98*g*mol^-1)` `=` `1.12*mol`.

Given the stoichiometry, `3/2xx1.12*cancel(mol)xx22.4*L*cancel(mol^-1)` are generated.