Chemistry - Mole Concept Question with Solution | TestHub

ChemistryMole ConceptEmpirical and Molecular FormulaMedium2 minQB
ChemistryMediumsingle choice
Passage / Comprehension

A mixture of three gases an alkane (general formula ), an alkene (general formula ) and was subjected to sparking to cause combustion of both the hydrocarbon at . After the reaction three gases were present and none of the hydrocarbon remained. On passing the gases through KOH (absorb ), an increment in mass of KOH solution by 132 gm was observed. The remaining gases were passed over white anhydrous and the weight of blue hydrated crystals was found to be 72 gm more than that of white anhydrous . Given that initially total 10 moles of the three gases were taken and moles of alkane and alkene were equal and if molecular mass of alkene - molecular mass of alkane i.e. ), then answer the following questions. (Show calculations)

What is the molecular formula of the two hydrocarbon.

Options:

Answer:
C
Solution:

Given, .

For alkane = CH and alkene = CH, molecular masses are and , respectively.

So, .

Using the products formed, mol and mol with equal moles of hydrocarbons, we get .

Hence, the hydrocarbons are CH₄ and C₂H₄.

Correct option: (C) CH₄, C₂H₄

Stream:JEESubject:ChemistryTopic:Mole ConceptSubtopic:Empirical and Molecular Formula
2mℹ️ Source: QB

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