Question: Metal T reacts with water to produce a colourless solution. A white precipitate is produced when thi...

Question

Metal T reacts with water to produce a colourless solution. A white precipitate is produced when this colourless solution is mixed with aqueous sulphuric acid. What is metal T?
(A) Barium
(B) Magnesium
(C) Potassium
(D) Sodium

Answer 1

Solution

Precipitate: It is defined as the solid formed as a product in the reaction of solution. For example: when sodium hydroxide reacts with hydrochloric acid then a white precipitate of sodium chloride is formed. Reaction is as $NaOH + HCl \to NaCl + {H_2}O$ .

Complete step by step solution:
First of all we will talk about metals, non-metals and their properties.
Elements: A substance which cannot be broken down further by chemical and physical method, is called an element. They are made up of atoms. All the atoms in an element are of the same kind.
Elements are classified into two categories:
Metals and Non-metals.
Here we are given with the metal. It is given that when this metal reacts with water then it forms a colourless solution. Now here we are given options barium, magnesium, potassium and sodium. So now we also know that when sodium or potassium reacts with water then the metal is set on fire producing hydrogen and sparks. Hence option c and d are incorrect.
Now magnesium reacts with water and it forms magnesium oxide (which is a white solid) and hydrogen gas. Since during this reaction a white solid is formed hence option b is also not correct. Now coming to option a i.e. barium. The reaction of b arium with water is as follows:
$Ba + 2{H_2}O \to Ba{(OH)_2} + {H_2}$ . Here the product formed i.e. $Ba{(OH)_2}$ is colourless solution and when this solution reacts with sulphuric acid it forms a white precipitate the reaction is as
$Ba{(OH)_2} + {H_2}S{O_4} \to BaS{O_4}$ .
Hence option A is correct.

Note:
Some physical properties of metals and non-metals are as: Metals are shiny in nature, malleable, ductile, react with oxygen and so many others while non-metals are not shiny, non-malleable, non-ductile, generally do not react with oxygen or air, generally blurred to see.