Cambridge IGCSE 0620: Acids, Bases, Salts & The pH Scale | Tutolia Study Library

Characteristics of acids and bases, proton donors/acceptors, neutralisation, indicators, and salt preparation methods for IGCSE Chemistry 0620.

Subject: Chemistry | Grade Level: Grade 9-10 (IGCSE) | Curriculum: Cambridge IGCSE

Cambridge IGCSE: Acids, Bases, Salts & The pH Scale (Chemistry)

Syllabus Code: 0620 · Topic Code: 8.1 · Level: Grade 9-10 (IGCSE)

Aligned with official Cambridge IGCSE examination standards and assessment objectives.

🎯 Official Syllabus Learning Objectives

Candidates should be able to:

• [x] Define acids as proton donors (H+ ions in solution) and bases as proton acceptors (OH- ions in solution)
• [x] Describe the pH scale from 0 to 14 and use indicators (litmus, methyl orange, thymolphthalein)
• [x] Select appropriate salt preparation methods (excess insoluble base, titration, precipitation)

📐 Essential Formulas & Mathematical Equations

$

\text{Acid} + \text{Base} \rightarrow \text{Salt} + \text{Water}

$

$

\text{Acid} + \text{Metal} \rightarrow \text{Salt} + \text{Hydrogen}

$

$

\text{Acid} + \text{Carbonate} \rightarrow \text{Salt} + \text{Water} + \text{CO}_2

$

💡 Conceptual Breakdown & Core Revision Notes

Mastering Acids, Bases, Salts & The pH Scale is critical for scoring Grade 9 / A* in Cambridge IGCSE Chemistry. When preparing for exam papers, examiners prioritize precise definitions, proper scientific command-word execution (State, Describe, Explain, Evaluate), and dimensional unit consistency.

Methodical Problem-Solving Framework

1. List Given Variables: Write down all given quantities with their respective SI units and identify the target variable.
2. Standardise Units: Always convert non-standard units (e.g. grams to kilograms, centimeters to meters, cm³ to dm³, hours to seconds).
3. State the Base Formula: Always state the general equation explicitly before substituting numbers to secure method marks.
4. State Final Value with Units: Quote your final calculated value to the required number of significant figures (typically 2 or 3 significant figures in Cambridge & IB) followed by the correct unit.

⚠️ Examiner Warnings & Common Student Pitfalls

Chief Examiner Advice:

All nitrates and all sodium/potassium/ammonium salts are soluble in water. Insoluble salts are prepared by precipitation.

📝 Worked Exam Exemplar (Mark Scheme Breakdown)

Question:

Describe how to prepare pure, dry crystals of hydrated copper(II) sulfate starting from copper(II) oxide and dilute sulfuric acid.

Model Answer & Marking Rubric:

1. Add excess CuO to warm dilute H₂SO₄. 2. Filter to remove unreacted CuO. 3. Heat filtrate to saturation point. 4. Allow to cool and crystallize, filter and dry with filter paper.

🧠 Rapid Active-Recall Study Deck (Spaced Repetition)

Test your immediate retention before leaving this page:

1. Question: What is the fundamental definition associated with Acids, Bases, Salts & The pH Scale?

Answer: Check the primary learning objective in the checklist above.

1. Question: Which governing formula links the main physical quantities in this topic?

Answer: `\text{Acid} + \text{Base} \rightarrow \text{Salt} + \text{Water}`.

1. Question: What classic trap do examiners frequently set on this topic?

Answer: All nitrates and all sodium/potassium/ammonium salts are soluble in water. Insoluble salts are prepared by precipitation.