Question

For the reactions between HCl and magnesium, describe the initial appearance of the metal and identify the evidence of a chemical reaction. Write out all coefficients, including coefficients of 1.

Answer 1

Magnesium metal initially appears shiny and silvery, and the reaction with hydrochloric acid produces hydrogen gas, heat, and a clear solution of magnesium chloride. The balanced equation is Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g).

Step-by-step explanation:

The initial appearance of magnesium metal before reacting with hydrochloric acid is a shiny, silvery substance. When magnesium reacts with hydrochloric acid (HCl), evidence of a chemical reaction includes the disappearance of the solid metallic magnesium, the evolution of bubbles of hydrogen gas (H2), the production of heat, and the formation of a clear solution containing magnesium chloride (MgCl2). The balanced chemical equation for the reaction is:

Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g)

It is important to note that the coefficients of 1 are not written in the chemical equation. This reaction also indicates a single replacement reaction and an exothermic reaction, as heat is evolved during the process.