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Question
Dilute NaOH can be tested with
(a) red litmus paper
(b) blue litmus paper
(c) lime water
(d) Na2CO3
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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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