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A water sample has ppm level concentration of following anions F – = 10 ; − 2 4 SO = 100 ; − 3 NO = 50 The anion / anions that make / makes the water sample unsuitable for drinking is / are

1. Only F –
2. Only − 2 4 SO
3. Only − 3 NO
4. Both − 2 4 SO and − 3 NO

Correct answer: Only F –

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