Question

When aluminum, AlAl, metal is dipped in an aqueous solution of hydrochloric acid, HClHCl, hydrogen gas, H2H2, is produced with the formation of an aluminum chloride, AlCl3AlCl3, solution. Write the balanced chemical equation showing the phases of reactants and products.

Answer 1

Answer:

Balanced equation: $2Al(s)+6HCl(aq.)\rightarrow 2AlCl_{3}(aq.)+3H_{2}(g)$

Explanation:

• Al is an metallic species with a standard reduction potential of -1.66 V( $E_{Al^{3+}\mid Al}^{0}=-1.66V$).
• $H_{2}$ is present at the intermediate position in electrochemical series with a standard reduction potential of 0 V ($E_{H^{+}\mid H_{2}}^{0}=0V$).

• So, when Al is dipped in aqueous solution of HCl, Al is readily oxidized to produce $Al^{3+}$ whereas $H^{+}$ is reduced to $H_{2}$ .
• Hence, as a whole, aqueous $AlCl_{3}$ and gaseous $H_{2}$ is produced as products.

Balanced equation: $2Al(s)+6HCl(aq.)\rightarrow 2AlCl_{3}(aq.)+3H_{2}(g)$