🧫 Required Practicals (Paper 1) Flashcards
(10 cards)
How do you separate a salt solution using crystallisation?
Heat solution to evaporate water. Let it cool. Crystals form and can be filtered.
How do you separate a mixture of sand and salt?
Add water (salt dissolves). Filter to remove sand. Evaporate water from salt solution.
How paper chromatography work?
Different dyes travel at different speeds. Calculate Rf value = distance spot ÷ distance solvent.
How do you measure temperature change in a reaction?
Use a polystyrene cup. Record temperature before and after mixing reactants.
Why are practicals repeated and averaged?
To improve accuracy and identify anomalies.
What safety measures are needed in neutralisation experiments?
Wear goggles. Use dilute acids and bases. Handle glassware with care.
Why is only one drop of indicator used in titrations?
Too much would affect the results; a single drop shows a clear colour change.
How is a soluble salt made from an acid and an insoluble base?
Add excess base to acid. Filter out solid. Evaporate water to crystallise.
What is a control variable and why is it important?
It’s kept constant to ensure a fair test and reliable results.
Why are polystyrene cups used in temperature change experiments?
They insulate to reduce heat loss.
