Odd one outHard1 mark
1(e)
Choose the ODD one out of the following terms given and name the CATEGORY to which the others belong:
Formalin, Iodine, DDT, Lime
Topic: Disinfectants
Previous-year question practice database
Answer
Exam answer
Odd term: IODINE. Category of the others: DISINFECTANTS.
Explanation
Formalin, DDT and lime are all DISINFECTANTS — strong chemicals used on NON-LIVING surfaces and surroundings to destroy germs and pests.
IODINE (as tincture of iodine) is an ANTISEPTIC — a MILD chemical applied to LIVING TISSUE, on wounds and skin.
THE DISTINCTION, which the 2018 paper also tests: DISINFECTANTS — on OBJECTS and SURFACES; strong. Formalin, cresol, phenol, bleaching powder, lime. ANTISEPTICS — on LIVING TISSUE; mild. Iodine, Dettol, mercurochrome.
Ask of each: could this safely be put on a cut? If yes it is an antiseptic; if no, a disinfectant.
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