Definitions

Cards (21)

  • Acid:
    • Acids produce hydrogen ions (H+) in aqueous solutions
    • pH range of 0-6
  • Alkali:
    • Alkalis produce hydroxide ions (OH-) in aqueous solutions
    • pH range of 8-14
  • Crystallisation:
    • Separation technique to produce solid crystals from a solution by evaporating the solvent
  • Displacement:
    • A chemical reaction where a more reactive element displaces a less reactive element from its compound
  • Electrolysis:
    • Splitting up of an ionic compound using electricity
    • Chemical reactions occur at the electrodes and materials decompose
  • Electrolyte:
    • Solution containing free ions from molten or dissolved ionic substance
    • Ions are free to move to carry charge
  • Extraction:
    • Techniques used to separate a desired substance when mixed with others
  • Filtration:
    • Separation technique to separate solids from liquids
  • Negative electrode (cathode):
    • Electrode where hydrogen is produced if the metal in the electrolyte is more reactive than hydrogen
    • Positively charged ions gain electrons, reactions are reductions
  • Neutralisation:
    • Reaction when an acid and a base react to form water and a salt
  • Oxidation:
    • Reaction involving the gain of oxygen
    • Loss of electrons
  • pH scale:
    • Measure of acidity or alkalinity of a solution from 0 to 14
    • Can be measured using universal indicator or a pH probe
  • Positive electrode (anode):
    • Electrode where oxygen is produced unless the solution contains halide ions, then the halogen is produced
    • Negatively charged ions lose electrons, reactions are oxidations
  • Reduction:
    • Reaction involving the loss of oxygen
    • Gain of electrons
  • Reduction with carbon:
    • Metals less reactive than carbon can be extracted from their oxides by reduction with carbon
  • Strong acid:
    • Completely ionised in aqueous solution
    • Examples: hydrochloric, nitric, and sulfuric acids
  • Reactivity series:
    • Metals arranged in order of reactivity
    • Used to predict products from reactions
  • Universal indicator:
    • Mixture of dyes that changes color gradually over a range of pH
    • Used in testing for acids and alkalis
  • Weak acid:
    • Partially ionised in aqueous solution
    • Examples: ethanoic, citric, and carbonic acids
  • Redox reaction:
    • Reaction where both oxidation and reduction occur simultaneously
  • Titration:
    • Technique using a solution of known concentration to determine the concentration of an unknown solution