Chemistry - Mole Concept Question with Solution | TestHub

ChemistryMole ConceptEmpirical and Molecular FormulaEasy2 minQB
ChemistryEasystatement

Statement-1: When of a hydrocarbon undergoes complete combustion, it produces of and of . The empirical formula of the hydrocarbon is .

Statement-2: The molecular formula of a compound can be determined if its empirical formula and molar mass are known.

Options:

Answer:
D
Solution:

Statement-1:

Mass of C in CO₂ =

Mass of H in H₂O =

Total mass of C and H = .

This does not match the given hydrocarbon.

If we use the calculated masses, moles of C = mol. Moles of H = mol.

Ratio C:H = . Empirical formula is C₃H₈, not CH₃. So, Statement-1 is false.

 

Statement-2: The molecular formula is a multiple of the empirical formula. If the empirical formula and molar mass are known, the molecular formula can be determined by finding the integer 'n' such that (Empirical Formula Mass) = Molar Mass. So, Statement-2 is true.

 

Therefore, Statement-1 is false and Statement-2 is true.

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

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