Question

Solve this Stoichiometry problem

Solve the following problem showing all of your work and including all units. You can solve the problem in several steps or as a tandem conversion problem.

How many grams of Br2 are needed to completely convert 15.0 g Al to AlBr3 ?

Al (s) + Br2 (l) --> AlBr3 (hint: the equation is not balanced)

Answer 1

Answer : The balanced equation is;

2Al + 3
`Br_(2)` ----> 2Al
`Br_(3)`.

So now, to calculate how many grams of
`Br_(2)` will be needed to completely convert 15 g of Al
`Br_(3)`,

In the reaction 2 moles of Al and 3 moles of
`Br_(2)` will be needed to produce 2 moles of Al
`Br_(3)`.

So, (15.0 g Al) X (1 mole Al / 26.98 g Al) X (3 moles
`Br_(2)` / 2 moles Al) X (159.81 g
`Br_(2)` / 1 mole
`Br_(2)`)

= 133 g
`Br_(2)`

Hence, 133g of
`Br_(2)` will be needed to completely convert 15 g of Al into Al
`Br_(3)`.