Other Common Questions (Copy)

In addition to diagram drawing, ion tests, titrations, and experiment design, Paper 6 includes a variety of recurring question types designed to assess your application of practical skills, observation analysis, and experimental reasoning. These are often 2–4 mark questions that test understanding of lab technique, safety, reliability, and data interpretation.

This section provides detailed examples, formats, and answering techniques for each commonly appearing question type.

🔁 1. Repeatability and Reliability Questions

What They Ask:

• “Why is the experiment repeated?”
• “How would you improve the reliability of the results?”

Correct Response Must Include:

• Repeat the experiment multiple times
• Calculate an average of the results
• Say:
  ✅ “To improve reliability”
  ✅ “To identify and reduce the effect of anomalous results”

Wrong answers to avoid:
❌ “To get better results” (too vague)
❌ “To make it accurate” (accuracy ≠ reliability)

📏 2. Accuracy and Improvement Questions

What They Ask:

• “How could this experiment be made more accurate?”
• “Suggest one change to improve the accuracy.”

Correct Response Examples:

• Use a pipette instead of a beaker for volume measurements
• Use a digital thermometer instead of analog
• Use a balance with 2 decimal places
• Use smaller intervals (e.g. 0.5 mol/dm³ instead of 1 mol/dm³ steps)

Avoid vague phrases:
❌ “Be more careful”
❌ “Use better equipment”

⚠️ 3. Safety Questions

What They Ask:

• “State one safety precaution for this experiment.”
• “Why is it important to wear goggles?”

Correct Answers (based on context):

• For acids/alkalis: wear goggles to protect eyes from splashes
• For heating: use tongs or wear heat-resistant gloves
• For flammable liquids: keep away from open flames
• For toxic/corrosive gases: perform in fume cupboard

✔️ Use specific terms: goggles, gloves, fume hood, tongs
❌ Avoid general terms like “stay safe”

🧪 4. Tests for Gases, Cations, Anions

These may appear as:

• “Complete the table of observations”
• “What test would you use to identify the gas?”
• “Write the ionic equation for the reaction.”

✔️ Be precise with:

• Gas tests:
  → O₂ relights glowing splint
  → CO₂ turns limewater milky
  → H₂ gives pop with lighted splint
  → NH₃ turns damp red litmus blue
• Ionic equations: Must show correct spectator ions removed
  → e.g. Ag⁺ + Cl⁻ → AgCl (s)

📊 5. Completing Tables of Results

What They Ask:

• “Complete the table with correct readings.”
• “Calculate the average from concordant titres.”

Tips:

• Record to 2 decimal places for burette readings
• Use correct units: cm³, g, s, °C
• Identify anomalous values and exclude from average

✔️ Use:
→ “Average of concordant values”
→ “Ignore rough titration”

📈 6. Graph Drawing or Interpretation

What They Ask:

• “Plot a graph of the data provided.”
• “What is the relationship shown by the graph?”
• “Calculate the gradient of the line.”

Key Tips:

• Label axes with quantity + units
• Use uniform scale, starting at zero
• Plot clearly with crosses (×)
• If asked:
  → Use graph to describe the trend: e.g., “rate increases with temperature”
  → Calculate gradient using:
  gradient = change in y / change in x

❓ 7. Inference Questions (“What can you conclude…?”)

What They Ask:

• “What does this result show?”
• “What conclusion can be drawn from the experiment?”

Correct Response Examples:

• “The higher the temperature, the faster the rate of reaction”
• “Zinc is more reactive than copper”
• “Hydrogen gas is produced when the metal reacts with acid”

✔️ Use comparative or scientific reasoning, not general opinions

🔍 8. Error and Anomaly Identification

What They Ask:

• “Which result is anomalous?”
• “Suggest a reason for the error.”

Correct Approach:

• Look for data point that doesn’t fit the pattern
• Give plausible reason:
  • “Reading taken too early/late”
  • “Burette not rinsed properly”
  • “Gas escaped before bung was placed”

✔️ Be specific. Avoid vague phrases like “something went wrong”

🧠 9. Why Use…? / Choice of Apparatus

What They Ask:

• “Why is a conical flask used instead of a beaker?”
• “Why use a white tile in titration?”

Correct Answers:

• Conical flask: prevents splashing, easy to swirl
• White tile: makes color change easier to see
• Pipette: delivers fixed volume precisely
• Burette: allows controlled, measurable addition of liquid

🧪 10. Change of Conditions Questions

What They Ask:

• “How would increasing the temperature affect this experiment?”
• “What happens if you change the concentration?”

✔️ Use scientific principles to answer:

• “Rate of reaction increases due to more frequent collisions”
• “More gas produced in less time”
• “Crystals form faster but may be smaller”

🔁 11. Reversing or Extending the Experiment

What They Ask:

• “Suggest another variable to investigate.”
• “What other method could be used to measure this?”

✔️ Give variations such as:

• Changing temperature, surface area, or concentration
• Measuring mass lost instead of gas volume
• Using colorimeter for color change detection

📌 Final ATP-Style Answering Tips for Common Questions

✅ Always:

• Be precise (avoid vague answers like “better” or “faster”)
• Use scientific terms and units
• Break multi-part answers into clear, short points
• Base conclusions only on given data

❌ Never:

• Mix up observation and explanation
• Use informal language or unsupported guesses
• Leave out units, apparatus names, or variable types