Question

Assertion :20 g. of argon (atomic mass of $Ar=40$) occupies volume of 22400 cm${}^3$ at STP. Reason: 4 g. of helium (atomic mass of $He=4$) occupies a volume of 22400 cm${}^3$ at STP.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is D Assertion is incorrect but Reason is correct

Assertion

moles of Ar = $\frac{20}{40}=0.5$ moles

$1mole=22400c{m}^3$ at stp

$0.5mole=\frac{22400}{2}=11200c{m}^3$ at stp

so Assertion is incorrect

Reason :-

Moles of $He=\frac{4}{4}=1$

1 mole = $22400c{m}^3$ at stp

Assertion and Reason are not related to each other. Reason is correct