Assertion: One mole of NaCl contains 6.023 × 10^ 23 molecules of sodium chloride. Reason : 58.5 ~g of NaCl also contains 6.023 × 10^ 23 molecules of NaCl .

Correct answer: B. Ifboth assertion and reason are true but reason is not the correct explanation of assertion. Molar mass or mass of 1 mole of NaCl =23+35.5=58.5 ~g According to mole concept, 1 mole of molecules = Gram molecular mass =6.023 × 10^ 23 molecules 58.5 ~g of NaCl also contains 6.023 × 10^ 23 molecules of NaCl .

AIIMS 2015

Exam: AIIMS
Year: 2015
Subject: Chemistry
Chapter: Some Basic Concepts of Chemistry

AIIMS 2015 · Chemistry · Some Basic Concepts of Chemistry

Assertion: One mole of NaCl contains 6.023 × 10^ 23 molecules of...

Assertion: One mole of

\mathrm{NaCl}

contains

6.023 \times 10^{23}

molecules of sodium chloride. Reason :

58.5 \mathrm{~g}

\mathrm{NaCl}

also contains

6.023 \times 10^{23}

molecules of

\mathrm{NaCl}

Options

AIf both assertion and reason are true and reason is the correct explanation of assertion.
BIfboth assertion and reason are true but reason is not the correct explanation of assertion.
CIf assertion is true but reason is false.
DIf both assertion and reason are false.

Correct answer

B. Ifboth assertion and reason are true but reason is not the correct explanation of assertion.

Step-by-step solution

Molar mass or mass of 1 mole of

\mathrm{NaCl}

=23+35.5=58.5

\mathrm{~g}

According to mole concept, 1 mole of molecules = Gram molecular mass

=6.023 \times 10^{23}

molecules

\therefore 58.5 \mathrm{~g}

\mathrm{NaCl}

also contains

6.023 \times 10^{23}

molecules of

\mathrm{NaCl}

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