Acids, Bases and Salts — pH, Indicators and Everyday Chemicals

Sour, Bitter, and Worth Marks Every Single Cycle

An acid releases H⁺ ions in water. A base releases OH⁻ ions. A base that actually dissolves in water is called an alkali — so every alkali is a base, but not every base is an alkali. That one sentence has decided more statement-based questions than any formula in this chapter.

Why this topic earns its place in your revision: acids, bases and salts show up in SSC, Railway, CTET and BPSC TRE Part II almost every cycle, and the questions are recall-based, not calculation-based. That makes it one of the highest marks-per-hour topics in the whole general science section.

You are really learning three things at once — how to *identify* an acid or base (indicators), how *strong* it is (pH), and what *forms* when the two meet (salts). Every question you will ever see is a variation on one of those three.

1. Which acid is responsible for the sting of an ant?

2. The chemical formula of washing soda is

3. Plaster of Paris is prepared by heating gypsum to about

4. Phenolphthalein added to a sodium hydroxide solution will appear

5. Tooth decay begins when the pH of the mouth falls below

6. Which substance is used both as an antacid and in soda-acid fire extinguishers?

7. Bleaching powder is produced by the action of chlorine on

8. The pH scale was introduced by