Question

A metallic oxide reacts with water to form its hydroxides, hydrogen peroxide and also liberates oxygen. The metallic oxide could be:
A. $K{O_2}$
B. $N{a_2}{O_2}$
C. $CaO$
D. $L{i_2}O$

Answer 1

We must know that the Superoxide and peroxides of alkali metals are the one which forms hydrogen peroxide, hydroxides and also liberates oxygen when they react with the water.
We need to remember that the metal oxides are having polymeric structures. We need to know that the metal oxides are very strong due to metal oxide bond.

Complete step by step answer:
Let’s start the answer by writing an equation of the reaction that will happen, keeping the metal oxide as X.
Now, while solving this question one should we remember that superoxide and peroxides of alkali metals are the one which forms hydrogen peroxide, hydroxides and also liberates oxygen when they react with the water. Similarly in above case a metal oxide is reacting with water and one of the products is hydrogen peroxide, hydroxide and oxygen so the answer will be an alkali metal peroxide or superoxide.
It is also to be noted that superoxide and peroxides are stable when the atom they are connected with are bigger in size.
We need to know that the potassium peroxide is react with water to form potassium hydroxide, hydrogen peroxide as,
$2K{O_2} + 2{H_2}O \to 2KOH + {H_2}{O_2} + {O_2}$
So, the answer to this question will be option A. $K{O_2}$ .
We need to remember that when sodium peroxide react with water which forms hydrogen peroxide and oxygen as,
$N{a_2}{O_2} + {H_2}O \to 2NaOH + {H_2}{O_2}$
Therefore, the option B is incorrect.
When calcium oxide is react with water to form calcium hydroxide as,
$CaO + {H_2}O \to Ca{\left( {OH} \right)_2}$
Therefore, the option C is incorrect.
When lithium hydroxide reacts with water which forms lithium hydroxide as,
$L{i_2}O + {H_2}O \to 2LiOH$
Therefore, the option d is incorrect.

So, the correct answer is Option A.

Note: We must know that the hydrogen peroxide is a very useful chemical;we can use it as a mild antiseptic for disinfecting minor skin wounds, burns and cuts. Also we can use it as mouth rinse to remove mucus. It is also used as a swimming pool disinfectant. High concentration of Hydrogen peroxide can result in tissue burn.