Anirudh took two metal oxides; aluminium oxide and magnesium oxide as shown in the pictures given below.

Question

A. Anirudh took two metal oxides; aluminium oxide and magnesium oxide as shown in the pictures given below. But he forgot to label them. How will you guide/ help Anirudh to identify the oxides and label them?

B. In an activity Aishu was given two substances; Copper Sulphide (\(Cu_2S\)) and Copper Oxide (\(Cu_2O\)) to obtain copper from these compounds. She was able to extract Copper successfully. Illustrate with the help of chemical equations how Aishu might have completed the activity.

Answer 1

A. Aqueous solution of magnesium oxide turns red litmus to blue. Aluminium oxide is amphoteric and insoluble in water. Thus, it does not change the colour of either blue or red litmus.

OR

Magnesium oxide reacts with acid only whereas Aluminium oxide reacts with acids and bases, which are amphoteric. 

B. \(2cu_2s + 3O_2(g) \xrightarrow{Heat} 2Cu_2O(s) + 2SO_2(g)\)   

     \(2Cu_2O + Cu_2S \xrightarrow{Heat} 6Cu(s) + SO_2(g)\)