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#hydrocarbon

19 public questions tagged with this topic.

A hydrocarbon with 9 σ bonds produces 5 moles of CO₂ per mole upon combustion. What is its molecular formula?

5 carbons (from 5 CO₂). CH₃CH₂CH₂CH₂CH₃ (pentane) has 9 σ (8 C-H, 1 C-C from single bonds), no π, and fits C₅H₁₂.

Ref: NCERT Class 11 Chemistry > Chapter 8: Organic Chemistry - Some Basic Principles and Techniques > Topic: Fundamental Concepts - Reaction Mechanism - Fission and Reaction Intermediates

A hydrocarbon with a degree of unsaturation of 2 produces 4 moles of CO₂ per mole upon complete combustion. What is its

4 carbons (from 4 CO₂). Degree of unsaturation = 2 suggests two double bonds or one triple bond. CH₃C≡CCH₃ (but-2-yne, C₄H₆) fits with 2 π, 8 σ, and 4 CO₂.

Ref: NCERT Class 11 Chemistry > Chapter 8: Organic Chemistry - Some Basic Principles and Techniques > Topic: Electronic Effects - Inductive Mesomeric Hyperconjugation and Resonance

A 0.98 g sample of a hydrocarbon produces 3.08 g of CO₂ and 1.26 g of H₂O on complete combustion. What is its molecular

Mass of C ≈ 0.84 g; mass of H = 0.14 g. Total = 0.98 g. Moles: C = 0.07, H = 0.14; ratio = 1 : 2; empirical formula = CH₂, mass = 14 g/mol. n = 98/14 = 7; molecular formula = C₇H₁₄.

Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition

A 0.54 g sample of a hydrocarbon produces 1.76 g of CO₂ and 0.36 g of H₂O on complete combustion. If its molar mass is 5

Mass of C ≈ 0.48 g; mass of H = 0.04 g. Moles: C = 0.04, H = 0.04; ratio = 1 : 1; empirical formula = CH, mass = 13 g/mol. n ≈ 4; molecular formula = C₄H₄.

Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition

A 0.84 g sample of a hydrocarbon produces 2.64 g of CO₂ and 1.08 g of H₂O on complete combustion. What is its molecular

Mass of C ≈ 0.72 g; mass of H = 0.12 g. Total = 0.84 g. Moles: C = 0.06, H = 0.12; ratio = 1 : 2; empirical formula = CH₂, mass = 14 g/mol. n = 84/14 = 6; molecular formula = C₆H₁₂.

Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition

A 0.42 g sample of a hydrocarbon produces 1.32 g of CO₂ and 0.54 g of H₂O on complete combustion. What is its molecular

Mass of C ≈ 0.36 g; mass of H = 0.06 g. Total = 0.42 g. Moles: C = 0.03, H = 0.06; ratio = 1 : 2; empirical formula = CH₂, mass = 14 g/mol. n = 42/14 = 3; molecular formula = C₃H₆.

Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition

A 0.42 g sample of a hydrocarbon produces 1.32 g of CO₂ and 0.54 g of H₂O on complete combustion. What is its molecular

Mass of C ≈ 0.36 g; mass of H = 0.06 g. Total = 0.42 g. Moles: C = 0.03, H = 0.06; ratio = 1 : 2; empirical formula = CH₂, mass = 14 g/mol. n = 42/14 = 3; molecular formula = C₃H₆.

Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition