This key facts covers Formulations within Purity & Formulations for GCSE Chemistry. Revise Purity & Formulations in Chemical Analysis for GCSE Chemistry with 22 exam-style questions and 12 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 7 of 13 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
📋 Formulations
A formulation is a designed mixture — every ingredient is there for a reason, present in a carefully measured quantity. Formulations are NOT pure substances.
Common Formulations
- Paint: Pigment (colour), binder (adhesion), solvent (flow), additives (anti-mould)
- Medicines: Active ingredient (drug), binder (tablet shape), filler (size), coating (protection)
- Petrol: Hydrocarbon blend, octane improvers, antioxidants, detergents
- Alloys: Steel (iron + carbon), brass (copper + zinc), bronze (copper + tin)
- Cleaning products: Surfactants, enzymes, fragrances, preservatives
- Food products: Flavourings, preservatives, emulsifiers, vitamins
- Fertilisers: Nitrogen, phosphorus, potassium compounds in specific ratios
Practice questions for Purity & Formulations
In chemistry, what does it mean for a substance to be described as 'pure'?
Explain why the presence of impurities in a substance lowers its melting point and causes it to melt over a range of temperatures.