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Question
Dilute NaOH can be tested with
(a) red litmus paper
(b) blue litmus paper
(c) lime water
(d) Na2CO3
Solution
(a) red litmus paper
Sodium hydroxide when dissolved in water undergoes the following
reaction:
NaOH(s) + aqs → Na+(aq) + OH−(aq)
The dissociated OH− ions turn moist red litmus paper blue.
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