Question

Which of the following statements is/ are correct?
I. Coffee is bitter in taste hence, it is basic in nature.
II. All mineral acids are strong acids.
III. Phenolphthalein is a synthetic indicator.
IV. In neutralisation reaction, heat is always evolved.
V. If the soil is too basic, organic matter is added to it.

• A. III, IV and V
• B. I, III and V
• C. I, III and IV
• D. III only

Answer 1

The correct option is A III, IV and V

I. Coffee is bitter in taste but, it is acidic in nature.
II. All mineral acids are not strong acids. $HF$ and $H_{2}C{O}_3$ are weak mineral acids.
III. Phenolphthalein is a synthetic indicator which is colourless in acidic solution and turns pink in basic solution.
IV. Neutralisation reactions are exothermic in nature, thus, heat is always evolved in such reactions.
V. If the soil is too alkaline, then its alkalinity can be reduced by adding decaying organic matter which contains acidic substances.