Acids, bases and salt preparations

Worked examples (6)

• 1What are acids a source of? (Getting started)
• 2Base vs alkali (Getting started)
• 3Write the neutralisation ionic equation (Building confidence)
• 4Identify the products of neutralisation (Building confidence)
• 5Classify substances as acid, base or alkali (Stretch)
• 6Explain why one ionic equation fits all neutralisations (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended

Worked examples (6)

• 1Name the salt formed (Getting started)
• 2Complete the general word equations (Getting started)
• 3Balance an acid + metal equation (Building confidence)
• 4Acid + base, name salt and balance (Building confidence)
• 5Acid + carbonate with the gas test (Stretch)
• 6Predict, name and balance for an unfamiliar acid (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended

Worked examples (6)

• 1Write the equation for the reaction (Getting started)
• 2Put the method steps in order (Getting started)
• 3Explain why the base is added in excess (Building confidence)
• 4Explain the filtration step (Building confidence)
• 5Explain why you must not evaporate to dryness (Stretch)
• 6Hydrated vs anhydrous copper sulfate (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended

Worked examples (6)

• 1State the test and result for oxygen (Getting started)
• 2Identify the gas that turns limewater milky (Getting started)
• 3Distinguish ammonia from chlorine (Building confidence)
• 4Choose a test to tell hydrogen from carbon dioxide (Building confidence)
• 5Explain why a glowing splint relights in oxygen (Stretch)
• 6Identify four gases from their test results (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended

Worked examples (6)

• 1State the flame-test method (Getting started)
• 2Identify a metal ion from a flame colour (Getting started)
• 3Distinguish two metal ions with a flame test (Building confidence)
• 4Why anhydrous CuSO₄ does not prove purity (Building confidence)
• 5Prove a sample is pure water (Stretch)
• 6Identify a compound from its test results (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended

Worked examples (6)

• 1Identify a cation from its NaOH precipitate (Getting started)
• 2Test for a carbonate (Getting started)
• 3Distinguish chloride from iodide (Building confidence)
• 4Distinguish Fe²⁺ from Fe³⁺ (Building confidence)
• 5Tell apart two white precipitates (Stretch)
• 6Explain the 'acid first' step (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended