Core Concepts (Target: 'S' Pass)

• Define: What is a mixture?

• Identify: Is saltwater a homogeneous or heterogeneous mixture? Why?

• Name: In a sugar-water solution, what is the solute and what is the solvent?

• List: Name three different techniques used to separate mixtures.

• Recall: What separation technique is used to make tea?

• Define: What is an alloy?

Understanding & Application (Target: 'C' Pass)

• Explain: What is the difference between evaporation and simple distillation for separating a soluble solid from a liquid?

• Describe: List the steps you would take to separate a mixture of sand, salt, and water to obtain all three components separately.

• Apply: Which separation technique is most suitable for separating different coloured inks? Explain the basic principle.

• Explain: Why does sugar dissolve faster in hot tea than in iced tea?

• Relate: How is fractional distillation used in the petroleum industry?

Analysis & Higher-Order Thinking (Target: 'B' / 'A' Pass)

• Analyse: To electroplate an iron nail with copper, you are given an iron nail, a copper sheet, a battery, and connecting wires. What solution should you use as the electrolyte? Draw a labelled diagram of the setup.

• Justify: A student wants to extract a plant-based oil that is sensitive to high temperatures. Why would steam distillation be a better choice than simple distillation?

• Calculate: A solution is made by mixing 20 ml of alcohol with 80 ml of water. What is the volume fraction of alcohol in the final mixture?

• Synthesize: Describe how you could use the concept of solubility and filtration to determine if a sample of common salt is pure or if it is contaminated with fine sand.

O/L Exam Tip: For separation techniques, focus on the principle behind each method (e.g., difference in boiling points for distillation, difference in solubility for solvent extraction). Be ready to design simple separation procedures.