Question

Identify the correctly matched sets containing compound and its use from the following: \[ \text{I. Baking soda -- as mild antiseptic} \] \[ \text{II. Caustic soda -- in purification of bauxite} \] \[ \text{III. Washing soda -- in the manufacture of borax} \] The correct answer is (only):

• A. I, II, III
• B. I, II only
• C. II, III only
• D. I, III only

Hint:

Remember: \[ NaOH \rightarrow \text{Purification of bauxite} \] \[ Na_2CO_3 \rightarrow \text{Manufacture of borax} \] \[ NaHCO_3 \rightarrow \text{Antacid and baking powder} \]

Answer 1

The Correct Option is C

Concept: Important industrial uses of sodium compounds must be remembered.

Step 1: Examine Statement I. Baking soda is \[ NaHCO_3 \] Its common uses are:
• Baking powder
• Antacid
• Fire extinguishers It is not generally used as a mild antiseptic. Therefore Statement I is incorrect.

Step 2: Examine Statement II. Caustic soda is \[ NaOH \] In Bayer's process, bauxite is purified using concentrated sodium hydroxide solution. Hence Statement II is correct.

Step 3: Examine Statement III. Borax is manufactured using sodium carbonate (washing soda). Therefore Statement III is also correct. Thus only Statements II and III are correct. \[ \boxed{\text{II and III only}} \]