Choose the correct answer from each of the four options given below:
A strong chemical substance which is used on objects and surfaces in our surroundings to kill germs:
Topic: Disinfectants
Try it
Pick an option and check your answer. The full worked answer is below either way.
Answer
(a) Cresol.
CRESOL is a DISINFECTANT — a strong chemical used on OBJECTS AND SURFACES such as floors, drains and latrines to kill germs. It is too harsh to be applied to living tissue.
THE DISTINCTION being tested, and it is the whole question: DISINFECTANTS — used on NON-LIVING surfaces; strong. Cresol, phenol, bleaching powder. ANTISEPTICS — used on LIVING TISSUE, on wounds and skin; milder. Iodine (tincture), mercurochrome, Dettol.
Options (c) and (d) are both ANTISEPTICS, applied to cuts and grazes, which is why they are offered. Read the words "objects and surfaces" — they rule out anything meant for skin.
Carbolic acid (phenol) is a disinfectant too, but cresol is the answer given in the marking scheme.
Cresol.