Question

Which of the following indicate(s) a basic solution?
i. Litmus paper turns blue
ii. Phenolphthalein turns pink
iii. Hydronium ion concentration is greater than hydroxide ion concentration

• A. i only
• B. ii only
• C. iii only
• D. i and ii only
• E. i, ii and iii

Answer 1

The correct option is D i and ii only

The following indicates a basic solution

i. Litmus paper turns blue. In acidic medium, litmus is red in color whereas, in basic solution, litmus is blue in color.

ii. Phenolphthalein turns pink. In acidic medium, phenolphthalein is colourless. In a basic medium, phenolphthalein is pink in colour.

Note: In an acidic solution, Hydronium ion concentration is greater than hydroxide ion concentration. However, we need an indicator that will tell us if the solution is acidic or basic.