Question

The gaseous product formed when magnesium reacts with boiling water is:
a.) Hydrogen
b.) Washing soda
c.) Sulfurous
d.) Calcium Oxide

Answer 1

The reaction of magnesium with hot boiling water is as follows: $Mg\left( s \right) + 2{H_2}O\left( {aq} \right)\xrightarrow{{}}Mg{\left( {OH} \right)_2}\left( s \right) + {H_2}\left( g \right)$ . As we can see that hydrogen $\left( {{H_2}} \right)$ gas is released when magnesium reacts with hot boiling water.

Complete step by step answer:
Magnesium is an element with atomic number 12 and the symbol $Mg$ . It is gray which normally remains in solid-state and has crystalline form. It belongs to group 2 of the periodic table. It is the 9th most abundant element in the universe.
Magnesium when placed in cold water, it does not react at all (i.e. it is insoluble in cold water)
$Mg + {H_2}O\left( {cold} \right)\xrightarrow{{}}$ No reaction
This does not mean that magnesium does not react with water at all and as we increase the temperature of the water the rate of reaction with magnesium increases.
The reaction of solid magnesium with hot boiling water is shown below
$Mg\left( s \right) + 2{H_2}O\left( {aq} \right)\xrightarrow{{}}Mg{\left( {OH} \right)_2}\left( s \right) + {H_2}\left( g \right)$

This magnesium hydroxide is insoluble in water and shows the basic character (it turns phenolphthalein to pink color).
We can see in the reaction above that hydrogen $\left( {{H_2}} \right)$ gas is released when magnesium reacts with hot boiling water. When we hold a lit matchstick over this reaction mixture, we will hear the pop sound of hydrogen burning.
So, the correct answer is “Option A”.

Note: Magnesium is a fairly important element. Magnesium compounds like magnesium oxide are used in refractory material in furnace coating for producing steel, iron, glass, and cement. Other magnesium compounds are used in chemical, construction, and agricultural industries. The Grignard reagent is a compound made with magnesium and finds use in making alcohol.