Question

Robert places a piece of magnesium metal (Mg) into a test tube of hydrochloric acid (HCl). The magnesium begins to bubble and fizz, releasing hydrogen gas (H2) and the test tube gets warm. Which equation represents the reaction Robert observed?

Answer 1

Answer:

See below.

Explanation:

The balanced equation is

Mg(s) + 2HCl ---->   MgCl2 + H2(g)

Answer 2

Answer:

$Mg_{(s)} + 2HCl_{(aq)} ---> MgCl_2_{(aq)} + H_2_{(g)}$

Explanation:

The reaction is a simple replacement reaction in which hydrogen gas is liberated when it gets replaced by Magnesium in aqueous solution of hydrochloric acid.

1 mole of Mg reacts with 2 moles of HCl to give 1 mole $MgCl_2$ and 1 mole $H_2$ gas. The balanced equation for the reaction Robert observed is as follows:

 $Mg_{(s)} + 2HCl_{(aq)} ---> MgCl_2_{(aq)} + H_2_{(g)}$