Question

Following observations were made when different indicators were added to three unknown solutions A, B and C. Choose the option depicting the correct set of compounds for A, B and C.

• A. A: HCl ; B: NaOH ; C: C₆H₁₂O₆
• B. A: NaOH ; B: HCl ; C: C₆H₁₂O₆
• C. A: C₆H₁₂O₆ ; B: NaOH ; C: HCl
• D. A: HCl ; B: C₆H₁₂O₆ ; C: NaOH

Answer 1

The correct option is C

A: C₆H₁₂O₆ ; B: NaOH ; C: HCl

• Substance A shows no visible colour change with phenolphthalein, thus it can be inferred that it is acidic or neutral.

• Since it shows no change with the methyl orange indicator too, it is neutral in nature.

• Substance B turns pink when added to the phenolphthalein indicator, thus it can be inferred that it is basic in nature.

• Since it turns the methyl orange indicator yellow, it can be concluded that it is a base.

• Substance C shows no visible colour change with phenolphthalein, thus it can be inferred that it is acidic or neutral.

• Since it turns the methyl orange indicator red, it can be confirmed that it is acidic in nature.