Question

Based on the data given in the table below, identify substances A and B.

Substance A Substance B

Sour in taste	Bitter in taste
Obtained from minerals	Soapy to touch
Water-soluble	Water-soluble

• A.
  A: Nitric acid;
  B: Sodium hydroxide
• B.
  A: Hydrochloric acid;
  B: Magnesium hydroxide
• C.
  A: Oxalic acid;
  B: Calcium hydroxide
• D.
  A: Citric acid;
  B: Magnesium hydroxide

Answer 1

The correct option is A

A: Nitric acid;
B: Sodium hydroxide
Here we have to identify the nature of substances A and B on the basis of given characteristics:

• Since substance A has a sour taste, it must be an acid while B has a bitter taste, it must be a base.
• Substance A is an acid which is obtained from minerals, thus it is an inorganic or mineral acid.
• Nitric acid is that acid which is obtained from minerals and soluble in water while citric acid and oxalic acid are obtained from natural sources, so these are organic acids.
• Bases are bitter in taste and soapy to touch.
• Sodium hydroxide is that base which is soluble in water and is soapy to touch.
• Magnesium hydroxide and calcium hydroxide are bases that are insoluble in water.
• Hence substance A is nitric acid and substance B is sodium hydroxide.

So, the correct option is - option A.