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Overview of AQA GCSE Chemistry Paper 1

Apr 30, 2025

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AQA GCSE Chemistry Paper 1 Overview

Covers topics 1 to 5: Atoms, Bonding, Quantitative Chemistry, Chemical and Energy Changes. It applies to Higher and Foundation Tiers in Combined Trilogy and Triple Separate Chemistry.

Atomic Structure

  • Atoms: Basic units of elements, represented in the periodic table by symbols.
  • Compounds: Substances with two or more different atoms chemically bonded (e.g., H₂O).
  • Chemical Reactions: Atoms change bonds through reactions, needing balanced equations for conservation of mass.

Balancing Equations

  • Start with atoms in compounds, adjust with coefficients to achieve equal atoms on both sides.

Mixtures and Separations

  • Mixtures: Combination of elements and compounds not chemically bonded (e.g., air).
  • Separation Techniques:
    • Filtration: Separate large insoluble particles.
    • Crystallization: Obtain solute after solvent evaporation.
    • Distillation: Separation by boiling points.
    • Fractional Distillation: Separate different liquids by boiling points.

States of Matter

  • Solid, Liquid, Gas: Based on particle arrangement and energy.
  • Physical Changes: Melting, evaporating involve energy supply without new substances.
  • State Symbols: (s), (l), (g), (aq) indicate states in equations.

Atomic Models

  • Development: From Thompson’s plum pudding model to Rutherford’s nuclear model.
  • Subatomic Particles: Protons (+1), Neutrons (0), Electrons (-1).

Periodic Table

  • Atomic Number: Number of protons, determines element.
  • Mass Number: Protons + Neutrons.
  • Isotopes: Same element, different neutrons.

Electron Configurations

  • Electrons exist in shells; configurations help determine reactivity and bonding.

Groups in the Periodic Table

  • Group 1: Alkali metals; reactivity increases down group.
  • Group 7: Halogens; reactivity decreases down group.
  • Group 0: Noble gases; generally unreactive.

Bonding

  • Metallic Bonding: Lattice of ions with delocalized electrons.
  • Ionic Bonding: Metal gives electrons to non-metal, forming ions.
  • Covalent Bonding: Non-metals share electrons.
  • Giant Covalent Structures: Diamond, Graphite, and other allotropes.

Quantitative Chemistry

  • Conservation of Mass: Mass of reactants equals mass of products.
  • Moles: A measure of substance amount.
  • Calculating Moles: Moles = mass (g) / RAM (or RFM).

Reactions and Yields

  • Percentage Yield: Actual product mass vs. theoretical maximum.
  • Atom Economy: Efficiency of producing desired products.

Energy Changes

  • Exothermic: Releases energy, increases temperature.
  • Endothermic: Absorbs energy, decreases temperature.

Electrolysis

  • Process: Breaking down substances using electricity.
  • Electrodes: Cathode attracts cations, anode attracts anions.

Titrations (Triple Only)

  • Technique to determine concentration of a solution.

Key Concepts

  • Reactivity Series: Determines how metals react and displace each other.
  • Redox Reactions: Oxidation and Reduction processes.

Practical Applications

  • Energy Profiles: Visualize energy changes in reactions.
  • Batteries and Fuel Cells: Chemical reactions produce voltage for power.

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