Question

A metal A, which is used in the thermite process, when heated with oxygen gives an oxide B, which is amphoteric in nature. Identify A and B. Write down the reactions of oxide B with $HCl$ and $NaOH$.

Answer 1

Hint: We know that the compound that can possibly act both as a corrosive and as a base as per Bronsted-Lowry Theory is supposed to be amphoteric.
Example: The water particle has hydrogen iotas and, consequently, could go about as a corrosive in a response. The oxygen atom in the water atom has two solitary sets, one of which could be utilized to frame a bond with a hydrogen ion and, in this way; the water particle could go about as a base in a response. Since water can possibly act both as a corrosive and as a base, water is amphoteric.

Complete step by step solution:
-Metal oxides which respond with the two acids just as bases to create salts and water are known as amphoteric oxides. Numerous metals, (for example, zinc, tin, lead, aluminum, and beryllium) structure amphoteric oxides or hydroxides. Amphoteric oxides likewise incorporate Lead (II) oxide, and zinc (II) oxide, among numerous others.
-Thermite is a pyrotechnic structure of metal powder, fuel and metal oxide. At the point when lighted by heat, thermite goes through an exothermic decrease in oxidation response. Aluminum is utilized in thermite measure due to its high breaking point and ease. At the point when warmed with oxygen, it gives aluminum oxide, which is an amphoteric substance, which means it can respond with the two acids and bases.
-Hence, A is aluminum and B is aluminum oxide.
Response of aluminum oxide with hydrochloric corrosive can be composed as follows:
\[A{l_2}{O_3} + 6HCl \to 2AlC{l_3}{\text{ }} + 3{H_2}O\]
Response of aluminum oxide with sodium hydroxide can be composed as follows:
\[A{l_2}{O_3} + 2NaOH \to 2NaAl{O_2} + {H_2}O\]

Note:We have to remember that amphoteric oxides are mixes of oxygen which shows both acidic just as fundamental qualities. These oxides while responding with corrosive goes through a balanced response to frame water and salt. This displays the essential property of the mixes. Also responds with the antacid to frame salt and water, displaying acidic property. Model: aluminum oxide.