Introduces the fundamental laws governing chemical reactions, including the conservation of mass and the laws of definite and multiple proportions.
Moles of urea = 6/60 = 0.1 mol. Volume = 0.3 L. Molarity = 0.1/0.3 ≈ 0.333 M.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
M₁V₁ = M₂V₂. 0.15 × 50 = M₂ × (50 + 150). M₂ = (0.15 × 50)/200 = 0.0375 M.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
Reaction: Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O. Moles of Mg(OH)₂ ≈ 0.1638 mol. 1 mol Mg(OH)₂ produces 1 mol MgCl₂; mass ≈ 15.56 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
Reaction: Ca(OH)₂ + H₂SO₄ → CaSO₄ + 2H₂O. Moles of Ca(OH)₂ ≈ 0.1838 mol. 1 mol Ca(OH)₂ produces 1 mol CaSO₄; mass ≈ 25 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
Reaction: 2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O. Moles of C₂H₆ ≈ 0.3667 mol. 2 mol need 7 mol O₂; 0.3667 mol need ≈ 1.2833 mol. Volume = 1.2833 × 22.4 ≈ 28.75 L.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
0.0894 (3 sig figs), 298.15 (5 sig figs), 0.0821 (3 sig figs). Result ≈ 324.67; limited to 3 sig figs (325).
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
Reaction: N₂ + 3H₂ → 2NH₃. Moles of H₂ = 3 mol. 3 mol H₂ need 1 mol N₂; actual N₂ = 1 / 0.6 ≈ 1.67 mol. Volume = 1.67 × 22.4 ≈ 37.41 L.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
Reaction: C + O₂ → CO₂. Moles: C ≈ 0.8333 mol, O₂ = 0.75 mol. O₂ limits; 0.75 mol CO₂ formed = 0.75 × 44 = 33 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
Reaction: H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O. Moles of NaOH = 8/40 = 0.2 mol. 2 mol NaOH need 1 mol H₂SO₄; 0.2 mol needs 0.1 mol. Mass = 0.1 × 98 = 9.8 g.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
Reaction: C₅H₁₂ + 8O₂ → 5CO₂ + 6H₂O. Moles of C₅H₁₂ = 11.2/72 ≈ 0.1556 mol. 1 mol produces 5 mol CO₂; 0.1556 mol produces 0.7778 mol. Volume = 0.7778 × 22.4 ≈ 17.42 L.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
M₁V₁ = M₂V₂. 0.25 × 200 = M₂ × (200 + 300). M₂ = (0.25 × 200)/500 = 0.1 M.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
Moles = 4.48/22.4 = 0.2 mol. Molar mass = 2/0.2 = 10 g/mol.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple
