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For 100 g: C = 36.36 g, H = 6.06 g, O = 57.58 g. Moles: C ≈ 3.03, H ≈ 6.06, O ≈ 3.6. Ratio ≈ 1 : 2 : 1; empirical formula = CH₂O.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
Reaction: CuO + CO → Cu + CO₂. Moles of Cu = 6.4/64 = 0.1 mol. 1 mol Cu from 1 mol CuO; mass = 0.1 × 79.5 = 7.95 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
0.0456 (3 sig figs), 273.15 (5 sig figs), 0.0821 (3 sig figs). Result ≈ 151.63; limited to 3 sig figs (152).
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
For 100 g: Na = 32.43 g, S = 22.52 g, O = 45.05 g. Moles: Na ≈ 1.41, S ≈ 0.704, O ≈ 2.82. Ratio = 2 : 1 : 4; empirical formula = Na₂SO₄.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
Reaction: Pb(NO₃)₂ + H₂SO₄ → PbSO₄ + 2HNO₃. Moles of Pb(NO₃)₂ = 33.1/331 = 0.1 mol. 1 mol Pb(NO₃)₂ produces 1 mol PbSO₄; mass = 0.1 × 303 = 30.3 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
Reaction: AgNO₃ + NaCl → AgCl + NaNO₃. Moles of AgCl = 5.75/143.5 ≈ 0.04 mol. 1 mol AgCl from 1 mol AgNO₃; mass = 0.04 × 170 = 6.8 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
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.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
Reaction: BaCl₂ + H₂SO₄ → BaSO₄ + 2HCl. Moles of BaCl₂ = 20/208 ≈ 0.0962 mol. 1 mol BaCl₂ produces 1 mol BaSO₄; mass = 0.0962 × 233 ≈ 22.41 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
For 100 g: C = 40 g, H = 6.67 g, O = 53.33 g. Moles: C ≈ 3.33, H ≈ 6.67, O ≈ 3.33. Ratio = 1 : 2 : 1; empirical formula = CH₂O.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
Reaction: Ca(OH)₂ + 2HCl → CaCl₂ + 2H₂O. Moles of CaCl₂ = 11.1/111 = 0.1 mol. 1 mol CaCl₂ from 1 mol Ca(OH)₂; mass = 0.1 × 74 = 7.4 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
Moles: C = 1 mol, O₂ = 1.25 mol. Moles of CO₂ = 22/44 = 0.5 mol; C used = 0.5 mol. Remaining C = 0.5 mol forms 0.5 mol CO; mass = 0.5 × 28 = 14 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
Reaction: MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂. Moles of Cl₂ = 1.42/71 = 0.02 mol. 1 mol Cl₂ needs 1 mol MnO₂; 0.02 mol needs 0.02 × 87 = 1.74 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Dalton's Atomic Theory and Atomic and Molecular Masses
