Initial Phenomena Question: Magnesium metal reacts with hydrochloric acid to produce magnesium chloride and hydrogen gas; how can you prove that?

See explanation

Explanation:

The reaction equation is as follows;

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

Firstly, the appearance of bubbles of gas shows that a gas is evolved in the reaction.

Secondly,  If we  hold up the flame of a butane fireplace lighter above the appearing hydrogen bubbles, we will hear audible pops as the hydrogen gas ignites showing that a combustible gas is produced in the reaction.

Lastly, as the reaction proceeds, the magnesium ribbon disappears as MgCl2 is formed. If a set up such as the image attached is used, hydrogen gas is collected over water.

Image credit: RSC education

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

3 1/4 %

explanation: