State whether the following statements are true or false. Correct the false statements.
(a) All substances are either acidic or basic.
(b) A compound if acidic will turn all indicators red.
(c) Lime water turns red limus blue.
(d) Common salt dissolved in water turns blue litmus red.
(e) Phenolphthalein is a natural indicator.
(f) Calamine can be used to treat ant’s sting.
(g) Lemon water is basic in nature.

AcademicChemistryNCERTClass 7

(a) False 
All substances are acidic, basic or neutral
(b) False
Acids do not give red colour with all indicators.
(c) True
As Lime water is basic in nature hence, it turns red litmus blue.
(d) False
Blue litmus does not change to red in common salt solutions since it is neutral.
(e) False
Phenolphthalein is a synthetic indicator.
(f) True
Ant’s sting contains formic acid hence can be neutralized by calamine solution, which contains zinc carbonate.
(g) False
Lemon water is acidic in nature.
raja
Updated on 10-Oct-2022 13:21:27

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