Question

________ turns blue litmus red whereas __________ turns red litmus blue.

Answer 1

Hint: The chemical substance which contains hydrogen and donates a proton or hydrogen ion to a base is termed acids. On the other hand, a base is a substance that can accept hydrogen from acid in a chemical reaction. The acids are usually sour in taste while bases are bitter in taste.

Complete answer:
There are many examples of acids and bases that we use in our everyday life.
- The orange contains citric acid.
- The curd contains lactic acid
- We use acetic acid or vinegar in many food preparations.
- The soap that we use every day is a base.
- Milk of magnesia is an example of base.

Whether a substance is an acid or base, it can be determined by testing its pH. The pH of a substance is measured by a pH scale. It ranges from 0-14. The acids have a pH between 0-7 while bases have a PH of more than 7. A neutral substance (neither acidic nor basic) has a pH value of 7. A substance having a pH value of 7 is the most basic substance while 0 indicates the most acidic substance.

Litmus paper test is another way to determine whether a substance is acidic or basic. Red litmus paper and blue litmus paper are two coloured litmus papers that are used to test the acid and base. In acidic conditions, the blue litmus paper turns red while in basic conditions, red litmus paper turns blue.

Thus, an acid turns blue litmus red whereas a base turns red litmus blue.

Note: When a strong acid and a strong base interact with each other, salt and water is formed. This is called a neutralization reaction. For example- when sodium hydroxide (NaOH) interacts with hydrogen chloride (HCl), sodium chloride (NaCl), which is a salt, is formed.