#KOH

CHEMISTRY

What is the pH of a 0.006 M KOH solution, assuming complete dissociation?

Given: What is the pH of a 0.006 M KOH solution, assuming complete dissociation? These values define the system as per NCERT data. Formula: [OH-] = 0.006 M, pOH = -log(0.006) approx 2.22. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: pH = 14 - 2.22 = 11.78 approx 11.8 . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Solutions, Topic: Concentration terms and colligative properties.

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CHEMISTRY

Which of the following undergoes the fastest elimination reaction with alcoholic KOH ?

Tertiary halides undergo elimination reactions faster due to greater stability of the carbocation intermediate. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.

Ref: NCERT Chemistry Textbook for Class XI and XII, Chapter: Some Basic Concepts, Structure of Atom and Periodicity, Topic: Mole concept, atomic models and periodic trends.

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Nature of C-X Bond and Methods of Preparation

Which halide on reaction with KOH in water forms CH₃CH(OH)CH₂CH₂CH₃ ?

Aqueous KOH substitutes Cl in CH₃CHClCH₂CH₂CH₃ (2-chloropentane) via SN₂ to form 2-pentanol ( CH₃CH(OH)CH₂CH₂CH₃ ).

Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation

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Types of Redox Reactions - Combination Decomposition Displacement

In the reaction 2MnO₂ + 2KOH + O₂ → 2K₂MnO₄ + H₂, which species is reduced?

Reduction involves electron gain. O (0 in O₂) becomes -1 in H₂ (via intermediate steps), gaining electrons.

Ref: NCERT Class 11 Chemistry > Chapter 7: Redox Reactions > Topic: Types of Redox Reactions - Combination Decomposition Displacement

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Acid-Base Theories - Arrhenius Bronsted-Lowry Lewis and Salts Hydrolysis

A 0.01 M solution of KOH is fully dissociated. What is its pH?

For KOH , [OH-] = 0.01 M = 10⁻² , pOH = -log(10⁻²) = 2 , pH = 14 - 2 = 12 .

Ref: NCERT Class 11 Chemistry > Chapter 6: Equilibrium > Topic: Acid-Base Theories - Arrhenius Bronsted-Lowry Lewis and Salts Hydrolysis

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Mole Concept and Molar Masses and Percentage Composition

How many grams of KOH are required to produce 7.45 g of KCl with excess HCl? (Molar masses: KOH = 56 g/mol, KCl = 74.5 g

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

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Laws of Chemical Combination - Conservation Mass Definite Multiple

A 0.15 M KOH solution is diluted by adding 150 mL of water to 50 mL of the original solution. What is the final molarity

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

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Laws of Chemical Combination - Conservation Mass Definite Multiple

A solution of KOH has a density of 1.1 g/mL and a molarity of 2 M. What is its molality? (Molar mass: KOH = 56 g/mol)

Mass of 1 L solution = 1000 × 1.1 = 1100 g. Mass of KOH = 2 × 56 = 112 g. Mass of water = 988 g = 0.988 kg. Molality = 2 / 0.988 ≈ 2.02 m.

Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Laws of Chemical Combination - Conservation Mass Definite Multiple

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Concentration Terms - Molarity Molality and Mole Fraction

A 0.1 M KOH solution is diluted by adding 200 mL of water to 100 mL of the original solution. What is the final molarity

M₁V₁ = M₂V₂. 0.1 × 100 = M₂ × (100 + 200). M₂ = (0.1 × 100)/300 ≈ 0.0333 M.

Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Concentration Terms - Molarity Molality and Mole Fraction

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