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Standard XII

Chemistry

Conductance and Conductivity

Assertion :A ...

Question

Assertion :A small amount of acid or alkali is added before electrolysis of water. Reason: Pure water is weak electrolyte.

Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

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Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.

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Assertion is correct but Reason is incorrect.

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Assertion is incorrect but Reason is correct.

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Solution

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
Water is a covalent compound, hence pure water is a weak electrolyte and feebly ionised and thus bad conductor of electricity.
However, addition of a small amount of acid or alkali increases ionisation of water making at good conductor of electricity.

For example, To increase the conductivity of water a few drops of sulphuric acid is added. Being a strong acid it can ionize completely to release H+ ions. These H+ ions are responsible for the conduction of electricity.

Hence, option A is correct.

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Similar questions

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(c) Assertion is correct, but reason is incorrect
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