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• Mole

  1 mole of any gas occupies a volume of 24 dm³ at room temperature (20°C) and pressure (1 atm)
• Calculating volume of gas from mass

  Calculate number of moles using mass and relative formula mass

  2. Multiply number of moles by 24 dm³/mol
• Mole


  Unit of measurement for the amount of a substance, equal to the amount of a substance that contains as many elementary entities (e.g. atoms, molecules, ions) as there are atoms in 0.012 kilograms of carbon-12
• Volume of gas


  One mole of any gas occupies a volume of 24 decimetres cubed at room temperature and pressure
• Calculating volume of gas

  Number of moles x 24 = volume in decimetres cubed
• atom economy=relative formula mass of desired product/relative formula mass of all reactants x100
• Titration

  A procedure to determine the concentration of an unknown solution by reacting it with a solution of known concentration
• Titration procedure


  1. Transfer 25 cm³ of sodium hydroxide solution into a conical flask

  2. Add 5 drops of indicator (e.g. methyl orange) to the alkali

  3. Place conical flask on a white tile

  4. Fill a burette with sulfuric acid

  5. Add acid to the alkali until the solution is neutral (colour change)

  6. Read the volume of acid added from the burette
• Reading the burette


  • Ensure eye is level with the surface of the liquid (meniscus)
  • Read at the bottom of the meniscus
• Normally, the titration is repeated several times until two readings within 0.1 cm³ are obtained, and the mean is taken as the final volume
• Knowing the volume and concentration of the alkali, and the volume of acid needed to neutralise it

  Allows calculation of the concentration of the acid
• Reactivity series:

  • potassium
  • sodium
  • calcium
  • magnesium
  • aluminium
  • carbon
  • zinc
  • iron
  • tin
  • lead
  • hydrogen
  • copper
  • silver
  • gold
• Reactivity series


  A series that shows the reactivity of different metals, determined by their reactions with water and acids
• Determining reactivity of metals

  1. React metals with water

  2. React metals with dilute acids

  3. Observe rate of reaction
• Potassium, sodium, and lithium react very rapidly with water
• Calcium reacts quite rapidly with water
• Magnesium, zinc, iron, and copper have no reaction with water at room temperature
• Potassium, sodium, and lithium react too vigorously with dilute acids to be safely tested
• Metals in order of decreasing reactivity with dilute acids

  • Calcium
  • Magnesium
  • Zinc
  • Iron
  • Copper
• Carbon and hydrogen are also included in the reactivity series, as they are used a lot in chemistry
• Reactivity of metals


  Depends on their ability to lose electrons and form positive ions
• Metals at the top of the reactivity series readily form positive ions, while metals at the bottom are much less likely to form positive ions
• Oxidation


  Loss of electrons
• Reduction


  Gain of electrons
• Magnesium atom forming magnesium ion


  1. Magnesium atom loses electrons

  2. Magnesium atom is oxidized
• Sulfur atom forming sulfide ion


  1. Sulfur atom gains electrons

  2. Sulfur atom is reduced
• Aluminium atom forming aluminium ion

  1. Aluminium atom loses 3 electrons

  2. Aluminium atom is oxidized
• Oxygen atom forming oxide ion

  1. Oxygen atom gains 2 electrons

  2. Oxygen atom is reduced
• Zinc reacting with copper sulfate: Zn+CuSO4→ZnSO4+Cu

  • Zinc atom is oxidized
  • Copper ion is reduced
• Half equations show oxidation or reduction of an element
• Acid


  A chemical that produces hydrogen ions (H+) in aqueous solution
• Base


  A chemical that can neutralize acids, producing a salt and water
• Alkali


  A soluble base that produces hydroxide ions (OH-) in aqueous solution
• Acid in aqueous solution

  1. Produces hydrogen ions (H+)

  2. Produces chloride ions (Cl-)

  3. Produces sulfate ions (SO4^2-)

  4. Produces nitrate ions (NO3-)
• Bases


  • Usually metal oxides or metal hydroxides
  • Can neutralize acids, producing a salt and water
• Alkali in aqueous solution(sodium hydroxide)

  1. Produces hydroxide ions (OH-)

  2. Produces sodium ions (Na+)
• pH scale


  • Measures the acidity or alkalinity of a solution
  • Acids have pH 0-6
  • Neutral solutions have pH 7
  • Alkaline solutions have pH 8-14
• Determining pH


  1. Using a pH probe

  2. Using universal indicator
• Neutralization reaction


  Acid (H+) + Alkali (OH-) → Salt + Water
• 3 types of Acids

  Hydrochloric acid, sulfuric acid, nitric acid