1 lt . of a hydrocarbon weighs as much as one litre of CO 2 . The molecular formula of the hydrocarbon is -

Question

1 lt . of a hydrocarbon weighs as much as one litre of CO 2 ​ . The molecular formula of the hydrocarbon is -

TestHub · Accepted Answer

Explain the question: Find a hydrocarbon with the same density as CO₂.

Concept: This question is based on Avogadro's law (equal moles, equal mass).

Solution: According to Avogadro's law, equal volumes of gases at the same temperature and pressure contain an equal number of moles. Since 1 L volumes of the hydrocarbon and CO₂ have the same mass ("weighs as much"), their molar masses must also be equal. The molar mass of CO₂ is $12 + (2 \times 16) = 44 g / m o l$ . We must find the hydrocarbon with a matching molar mass. Checking the options:

$C_{3} H_{8} = (3 \times 12) + (8 \times 1) = 36 + 8 = 44 g / m o l$

$C_{2} H_{6} = (2 \times 12) + (6 \times 1) = 24 + 6 = 30 g / m o l$

$C_{2} H_{4} = (2 \times 12) + (4 \times 1) = 24 + 4 = 28 g / m o l$

$C_{3} H_{6} = (3 \times 12) + (6 \times 1) = 36 + 6 = 42 g / m o l$

The hydrocarbon C₃H₈ matches the molar mass of CO₂. Final answer: A

Chemistry - Mole Concept Question with Solution | TestHub

Options:

Doubts & Discussion