C2 Elements, compounds and mixtures

Practice questions on Elements, compounds and mixtures

• Silicon dioxide is a giant covalent structure used to make glass and heat-resistant labora… (4 marks, Explain)
• Explain why graphite can conduct electricity but most other giant covalent structures, suc… (4 marks, Explain)
• Explain why sodium chloride has a high melting point. (4 marks, Explain)
• A perfume manufacturer claims that a particular fragrance ingredient is a pure substance. … (4 marks, Explain)
• A water treatment plant produces drinking water from river water. The river water contains… (4 marks, Describe)
• A food scientist is investigating whether a sample of red food colouring is pure or a mixt… (4 marks, Explain)
• A technician is testing two samples of aspirin — one freshly prepared in a laboratory and … (4 marks, Explain)
• A student is trying to separate two miscible liquids collected from a chemical reaction — … (4 marks, Explain)
• Graphite and diamond are both giant covalent structures made entirely of carbon atoms, yet… (4 marks, Explain)
• Explain why graphite can conduct electricity but diamond cannot, despite both being giant … (4 marks, Explain)
• Explain why ionic compounds such as sodium chloride have high melting points but do not co… (4 marks, Explain)
• Metals used in engineering are often alloys rather than pure metals. Explain why alloys ar… (4 marks, Explain)
• Poly(ethene) is a simple molecular substance used to make plastic bags. Explain why poly(e… (4 marks, Explain)