Hydrogen gas can be formed in the laboratory by the reaction of magnesium metal with hydrochloric acid (HCl). Write and balance the reaction for this process.

Mg (s) + 2HCl > H2(g) + MgCl2 (aq)

Explanation:

This reaction produces hydrogen gas and magnesium chloride. So, we have :

Mg (s) + HCl > H2 (g) + MgCl2 (aq)

In other to balance this reaction, we then add "2" to HCl on the left hand side of the equation so that the number of hydrogen and chlorine on both sides will be equal.

Thus our balanced equation would be:

Mg (s) + 2HCl (aq) > H2 (g) + MgCl2 (aq)

if you're asking what comes out, it's steam.