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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
0.0256 (3 sig figs), 273.15 (5 sig figs), 0.0821 (3 sig figs). Result ≈ 85.16; limited to 3 sig figs (85.2).
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition
Moles of gas ≈ 0.446 mol; molar mass ≈ 26 g/mol. Mass of C ≈ 0.922 g; C atoms per molecule adjusted to 1 (or 2 for C₂H₂). Molecular formula consistent with C₂H₂ (molar mass 26).
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition
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
Moles of gas ≈ 0.067 mol; molar mass ≈ 31.34 g/mol. Mass of C ≈ 0.72 g; C per molecule ≈ 1. H atoms ≈ 6 (adjusted). Molecular formula = C₂H₆.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition
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
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
Reaction: CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O. Moles of CaCO₃ = 0.1 mol; theoretical CO₂ = 0.1 mol. Actual CO₂ = 0.1 × 0.8 = 0.08 mol; volume = 0.08 × 22.4 = 1.792 L.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition
Moles of gas ≈ 0.1339 mol; molar mass ≈ 28 g/mol. Mass of C ≈ 1.44 g; C per molecule ≈ 1. H atoms ≈ 4 (adjusted). Molecular formula = C₂H₄.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition
Reaction: KOH + HCl → KCl + H₂O. Moles of KCl = 7.45/74.5 = 0.1 mol. 1 mol KCl from 1 mol KOH; mass = 0.1 × 56 = 5.6 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition
Moles of gas ≈ 0.0446 mol; molar mass ≈ 28 g/mol. Mass of C ≈ 0.6 g; C per molecule ≈ 1. H atoms ≈ 4 (adjusted). Molecular formula = C₂H₄.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition
For 100 g: C = 26.67 g, H = 2.22 g, O = 71.11 g. Moles: C ≈ 2.22, H = 2.22, O ≈ 4.44. Ratio = 1 : 1 : 2; empirical formula = CHO₂, mass = 45 g/mol. n = 90/45 = 2; molecular formula = C₂H₂O₄.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Mole Concept and Molar Masses and Percentage Composition
