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Laws of Chemical Combination - Conservation Mass Definite Multiple

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29 questions

How many grams of MgCl₂ are produced when 9.5 g of Mg(OH)₂ reacts with excess HCl? (Molar masses: Mg(OH)₂ = 58 g/mol, Mg

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

What is the mass of CaSO₄ produced when 13.6 g of Ca(OH)₂ reacts with excess H₂SO₄? (Molar masses: Ca(OH)₂ = 74 g/mol, C

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

What volume of O₂ at STP is required to burn 11 g of C₂H₆ completely to CO₂ and H₂O? (Molar mass: C₂H₆ = 30 g/mol)

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

What volume of N₂ at STP is required to react with 6 g of H₂ to produce NH₃ with 60% yield? (Molar mass: H₂ = 2 g/mol)

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

How many grams of H₂SO₄ are required to neutralize 8 g of NaOH completely? (Molar masses: H₂SO₄ = 98 g/mol, NaOH = 40 g/

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

What volume of CO₂ at STP is produced when 11.2 g of C₅H₁₂ is burned completely? (Molar mass: C₅H₁₂ = 72 g/mol)

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