Answer
Balanced equation:
$2Al(s) + 2H_3PO_4(aq) --\gt 2AlPO_4(aq) + 3H_2(g)$
Reaction type: Single replacement.
Work Step by Step
$Al(s) + H_3PO_4(aq) --\gt AlPO_4(aq) + H_2(g)$
1. Balance the number of hydrogen atoms, by putting a "3" in front of $H_2$ and a "2" in front of $H_3PO_4$.
$Al(s) + 2H_3PO_4(aq) --\gt AlPO_4(aq) + 3H_2(g)$
2. Balance the number of phosphorus atoms, by putting a "2" in front of $AlPO_4$.
$Al(s) + 2H_3PO_4(aq) --\gt 2AlPO_4(aq) + 3H_2(g)$
3. Balance the number of aluminum atoms, by putting a "2" in front of $Al$.
$2Al(s) + 2H_3PO_4(aq) --\gt 2AlPO_4(aq) + 3H_2(g)$
4. Classify the reaction.
That reaction follows the pattern for a single replacement reaction (A + BC −−> AC + B).
