Question

Assertion : One mole of NaCl contains 6.023 × 10²³ molecules of sodium chloride.
Reason : 58.5 g of NaCl also contains 6.023 × 10²³ molecules of NaCl.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (B)

Molar mass or mass of 1 mole of NaCl
$\quad\quad\quad\quad\quad\quad\quad\quad$= 23 + 35.5 = 58.5 g
According to mole concept,
1 mole of molecules = Gram molecular mass
$\quad\quad\quad\quad\quad\quad\quad\quad$= 6.023 × 10²³ molecules
∴ 58.5 g of NaCl also contains 6.023 × 10²³ molecules of NaCl.