24 public questions tagged with this topic.
Cr₂O₇²⁻ + 14H⁺ + 6e⁻ → 2Cr³⁺ + 7H₂O . 6 electrons per mole.
Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Variation of Conductivity with Concentration and Measurement
Mass of solute = (12/100) × 250 = 30 g .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Vapour Pressure and Raoult's Law - Ideal and Non-ideal Solutions
Moles of NaOH = (4/40) = 0.1 mol . Volume = 250 mL = 0.25 L. Molarity = (0.1/0.25) = 0.4 M .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Colligative Properties - Relative Lowering and Elevation of Boiling Point
i = 1 + α (n - 1) , where n = 3 . 2.2 = 1 + α (3 - 1) . 2.2 = 1 + 2α , α = (1.2/2) = 0.6 .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Abnormal Molar Masses and van't Hoff Factor
Moles of solute = (20/40) = 0.5 mol . Moles of water = (80/18) ≈ 4.444 mol . Total moles = 0.5 + 4.444 = 4.944. Mole fraction of solute = (0.5/4.944) ≈ 0.101 .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Abnormal Molar Masses and van't Hoff Factor
i = 1 + α (n - 1) , where n = 3 . 1.8 = 1 + α (3 - 1) . 1.8 = 1 + 2α , α = (0.8/2) = 0.4 .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Abnormal Molar Masses and van't Hoff Factor
Total mass = 20 g + 80 g = 100 g. Mass % = (20/100) × 100 = 20% , which matches the given value.
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Abnormal Molar Masses and van't Hoff Factor
i = 1 + α (n - 1) , where n = 2 . 1.6 = 1 + α . α = 1.6 - 1 = 0.6 .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Abnormal Molar Masses and van't Hoff Factor
Moles of acetone = (29/58) = 0.5 mol . Moles of water = (54/18) = 3 mol . Total moles = 0.5 + 3 = 3.5 . Mole fraction = (0.5/3.5) ≈ 0.143 .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Abnormal Molar Masses and van't Hoff Factor
Mass of C = (12/44) × 0.66 = 0.18 g. Percentage = (0.18/0.25) × 100 = 72%.
Ref: NCERT Class 11 Chemistry > Chapter 8: Organic Chemistry - Some Basic Principles and Techniques > Topic: Isomerism - Structural Isomerism - Chain Position Functional Metamerism
Moles of H₂SO₄ = 0.025 × 0.1 = 0.0025. Moles of NH₃ = 0.005 (2H per H₂SO₄). Mass of N = 0.005 × 14 = 0.07 g. Percentage = (0.07/0.36) × 100 ≈ 19.44%, which rounds to 19%.
Ref: NCERT Class 11 Chemistry > Chapter 8: Organic Chemistry - Some Basic Principles and Techniques > Topic: Electronic Effects - Inductive Mesomeric Hyperconjugation and Resonance
Kw = Ka × Kb = 1.0 × 10⁻¹⁴ , Kb = (1.0 × 10⁻¹⁴/1.2 × 10⁻²) = 8.33 × 10⁻¹³ .
Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Physical Equilibrium - Solid-Liquid Gas-Liquid and Henry's Law
