Question : The change in color of the moist litmus paper  in the given set up is due to

These are the options for the question:

i. presence of acid
ii. presence of base
iii. presence of H⁺(aq) in the solution
iv. presence of Litmus which acts as an indicator
(a) i and ii
(b) Only ii
(c) Only iii
(d) Only iv.

The correct answer is : (c) Only iii

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