Match List I (water quality) with List II (pH value):

List I

i.Neutral

ii.Moderately acidic

iii.Alkaline

iv.Injurious

List II

a.5

b.7

c.4

d.8

Ai-b, ii-c, iii-a, iv-d

Bi-a, ii-c, iii-b, iv-d

Ci-b, ii-a, iii-d, iv-c ✓ Correct

Di-c, ii-a, iii-b, iv-d

Correct answer: (C) i-b, ii-a, iii-d, iv-c

Explanation

Neutral water carries a pH of seven.

Moderately acidic water sits around a pH of five.

Alkaline water is marked by a pH of eight.

A pH of four is treated here as injurious to use.

The correct pairing links neutral to seven, mildly acidic to five, alkaline to eight and harmful to four.

The pH scale runs from zero to fourteen, with seven as the neutral midpoint.

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