GCSE Chemistry Edexcel Paper 1

Subdecks (2)

Cards (243)

  • What are the 3 states of matter?
    1. Solid
    2. Liquid
    3. Gas
  • How are covalent bonds formed?
    When 2 non-metals share a pair of electrons
  • Why does a chemical cell eventually stop producing a voltage?
    -It is an exothermic reaction and energy is transferred by electricity
    -When a reactant is used up, it goes 'flat
  • What are some compounds found in fertilisers?
    -Nitrogen - NH₄⁺
    -Phosphorus PO₄³⁻
    -Potassium - dissolve in water to form K⁺ ions
  • What is the theoretical yield of a reaction?
    The maximum amount of a product that can be formed from a reaction
  • How do you calculate the relative formula mass (Mr) from the relative atomic masses (Ar)?
    Ar of all elements added together
  • What is the symbol for corrosive?
  • What are some examples of common simple molecular covalent compounds?
    -Methane CH4
    -Water H2O
    -Hydrogen Flourine HF
    -Nitrogen Oxide NO2
  • What is an elctrolyte?
    An ionic substance with freely moving ions (molten or in solution)
  • How are cations formed?
    When electrons are lost
  • What happens in a reversible reaction?

    The reaction can proceed both forwards and backwards
  • What is the common reaction of metal with water?
    metal + water → metal hydroxide + hydrogen
  • How did Mendeleev arrange elements in a periodic table?
    By their properties and atomic mass
  • Where are transition metals positioned in the periodic table?

    The middle
  • What is the difference between a pure substance and a mixture?
    A pure substance is only made up of 1 substance (element or compound) that is chemically bonded.
    A mixture is made up of elements and compounds that do not react with each other and can be separated with physical processes.
  • How have Dalton's ideas about atoms changed?
    -Dalton thought that atoms were solid spheres that made up all matter and couldn't be created or destroyed. They were the smallest particle.
    -JJ Thompson discovered the electron in 1904, came up with the 'plum pudding' model-the atom was a solid positively charged sphere with negative electrons placed inside it
    -Rutherford did alpha scattering experiment in 1911. Fired alpha particles through thin gold foil and discovered atoms have a positively charged nucleus and electrons circle on orbits around it
  • How are anions formed?
    Electrons are gained
  • What is a chemical cell made up of?
    2 metals dipped in their salt solution
    A 'salt bridge' to allow ions to pass from one to another
    Voltage produced between metals
    Current flows when connected to an external circuit
  • How is ammonium nitrate made using ammonia from the Haber process?
    N₂+3H₂ ⇌ 2NH₃
    -Pressure of 200 atmospheres
    -Temp 400-450°c
    -Iron catalyst
  • What is the actual yield of a reaction?
    The amount of product obtained when you carry out an experiment
  • How do you calculate the empirical formula of a compound?
    -Mass of element/Ar
    -Divide both by smaller one to find simplest ratio
    -Find simplest whole number ratio
    -Write out formula
  • What is the symbol for irritant?
  • What changes happen between them?
    Solid - liquid = melting
    Liquid - gas = evaporating
    Solid - gas = sublimation
    Gas - solid = deposition
    Gas - liquid = condensing
    Liquid - solid = freezing
  • What are the properties of covalent simple molecular compounds?
    -Low melting and boiling point
    -Poor conductor of electricity
    -Often gas or liquid at room temperature
  • How did Mendeleev predict the existence and properties of elements yet to be discovered?
    By observing patterns in his periodic table and leaving gaps where patterns didn't matchSee an expert-written answer!We have an expert-written solution to this problem!
  • How are subatomic particles arranged in the nucleus?
    -Proton and neutron in nucleus
    -Electron on outer shells
  • What is the melting point of a pure substance?
    Sharp, will melt at one specific temperature as all particles will change from solid to liquid at the same time because they have the same melting point
  • What are some physical properties of transition metals?
    High melting point
    High density
    Malleable
    Ductile (can be drawn through wire)
  • What does the symbol ⇌ mean?
    It is a reversible reaction
  • What is the common reaction of metal with acid?
    metal + acidsalt + hydrogen
  • What happens during electrolysis?
    Compounds are split up using electricity
  • What is a molecule?
    A group of non-metal atoms joined by covalent bonds
  • What are the names of some common molecular elements?
    Oxygen
    Hydrogen
  • What are the main features of a hydrogen-oxygen fuel cell?
    -Fuelled by hydrogen and oxygen
    -Only product is water
    -Doesn't go 'flat', only stops when no more reactants are supplied
    -Overall reaction is 2H2(g) + O2(g) → 2H2O(l)
  • How is ammonium sulfate made on a small scale?
    1.Put some dilute sulfuric acid into a beaker.
    2.Add a few drops of methyl orange indicator.
    3.Add dilute ammonia solution drop by drop, stirring in between.
    4.Continue step 3 until the colour permanently changes from red to yellow.
    5.Add a few more drops of dilute ammonia solution.
    6.Pour the reaction mixture into an evaporating basin, and heat carefully over a boiling water bath.
    7.Stop heating before all the water has evaporated. Leave aside for crystals to form.
    8.Pour away excess water and leave the crystals to dry in a warm oven (or pat dry with filter paper).
  • How do you calculate percentage yield of a reaction?
    actual yield/theoretical yield x 100
  • What is the difference between empirical and molecular formula?

    -Molecular formula is the actual number of atoms in one molecule of a substance
    -Empirical formula is the simplest whole number ratio of elements in a compound
  • What is the symbol for harmful?
  • Why do covalent simple molecular compounds have low melting and boiling points?
    They have weak intermolecular forces that can be broken easily
  • How were Mendeleev's ideas supported by later evidence?
    In 1937 technetium was discovered with a relative atomic mass of 98. Mendeleev had left a gap in the table for an element with relative atomic mass of 98