Ibrahim applied sodium hydroxide to the lustrous, divalent element M. In the reaction mixture,he saw bubbles beginning to form. When hydrochloric acid was used to treat this element, herecorded the same findings. Tell him how to recognise the gas that was produced. For bothreactions, write chemical equations.

The gas produced in both reactions is hydrogen. Ibrahim can recognize this gas by using a burning splint test. When a burning splint is brought near the mouth of the test tube containing the gas, it will produce a 'pop' sound. This is a positive test for hydrogen gas.

The chemical equations for the reactions are:

1. When sodium hydroxide (NaOH) reacts with a divalent metal M (let's assume it's magnesium (Mg) for this example), it forms a metal hydroxide and hydrogen gas. The balanced chemical equation is:

Mg (s) + 2NaOH (aq) → Mg(OH)2 (s) + H2 (g)

2. When hydrochloric acid (HCl) reacts with magnesium (Mg), it forms a metal chloride and hydrogen gas. The balanced chemical equation is:

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

In both reactions, the hydrogen gas is released, which can be tested using the burning splint test.