2nd Chemistry Exam

1. Components
   1. Proton
   2. Neutron
   3. Electron

1. Oxygen
2. Uranium

1. Water
   1. Purifying
      1. 3 steps

         Anmerkungen:

         • Sedimentation Filtration Chlorination
   2. Testing
      1. for sulphate ions

         Anmerkungen:

         • Barium Chloride solution
      2. for halide ions

         Anmerkungen:

         • Silver Nitrate solution
2. 2 or more elements linked together

1. Group 1 Elements

   Anmerkungen:

   • Furthest left on the periodic tableMost reactive metalsReact strongly with OxygenReact violently with water Gain 1 electron to form ions
   1. Examples

      Anmerkungen:

      • Potassium Sodium Lithium
   2. Flame tests

      Anmerkungen:

      • Lithium-Red Sodium-Orange Potassium-Lilac
2. Group 7 Elements

   Anmerkungen:

   • Halogens2nd furthest to the rightUsed in pesticides, plastics and sterilisers Lose 1 electron to form ions
   1. Examples

      Anmerkungen:

      • Iodine Chlorine Fluorine
   2. Uses

      Anmerkungen:

      • Iodine-Antiseptic Chlorine-Sterilising swimming pool water
3. Transition elements
   1. Form different ions (2+, 3+ etc.)
   2. Form coloured solutions and compounds
   3. Iron (Fe)
      1. Can form a 2+ or 3+ ion
      2. Hydrated Iron(III) oxide=rust

1. Ionic

   Anmerkungen:

   • Bonding between a positively and a negatively charged ion
2. Covalent

   Anmerkungen:

   • The sharing of electrons
3. Metalic

   Anmerkungen:

   • Metal ions stuck together in a sea of delocalised electrons

1. 0 resistance

Anmerkungen:

• See book pages 166-171 and 174/5 Too long to talk about on this

1. Moles
   1. Molar masses
2. Percentage composition
3. Concentration

Anmerkungen:

• C6H12O6 would become CH2O You divide the bottom numbers by the highest common factor (in this case 2)

1. Dilution
   1. Formula

      Anmerkungen:

      • Starting Concentration ---------------------x Starting volume Target concentration
2. GDA (guideline daily amounts)

   Anmerkungen:

   • The amount of each substance that someone needs to be healthy
3. Titrations

   Anmerkungen:

   • Use indicators such as phenolphthalein.
4. pH curves

   Anmerkungen:

   • Shows the pH value of a solution in graphical form
5. Sulphuric acid
   1. Contact Process

      Anmerkungen:

      • 3 stages 3 key components (Sulphur, air and water) Conditions must be chosen appropriately

1. Measuring

   Anmerkungen:

   • Measure the volumes using a gas syringe and/or by counting bubbles Bubbles are very unreliable as there is no standard measurements for bubble size
2. Volumes

   Anmerkungen:

   • Directly proportional to the mass of reactants (double one and the other will double)

Anmerkungen:

• At equilibrium the reaction does not stop but the precise same number of reactions happen as counter-reactions The position of the equilibrium can be moved by: the concentration of reactants and products, the temperature changes or the pressure changes

1. Doesn't the picture look like Mrs Barnes and Mr Powell?

1. Weak acids and their uses

   Anmerkungen:

   • Example-Citric acid Use- limestone descaling
2. Strong acids and their uses

   Anmerkungen:

   • Example-Sulphuric acid Uses- Car batteries, chemistry catalysts
3. Strength of acids determined by the concentration of Hydrogen ions

Anmerkungen:

• The decomposition of stable compounds by using an electric current 2 Electrodes -Positive one is an anode which attracts negatively charged anions to it. -Negative one is a cathode which attracts positively charged cations to it

1. Fuel Cells

   Anmerkungen:

   • Usually use hydrogen and oxygen Don't need to explain how they work in great detail Applied elctrolysis
   1. Uses

      Anmerkungen:

      • Apollo 13 Fuel cells in space Fuel cells on Earth

Anmerkungen:

• Oxidation Is Loss of electronsReduction IsGain of electrons

1. Rusting

   Anmerkungen:

   • The hydration of Iron (III) Oxide
   1. Sacrificial protection

      Anmerkungen:

      • Example-galvanising (iron or steel) The outer coating gives up its electrons first "sacrificing" itself for what we want to protect

1. Fermentation

   Anmerkungen:

   • The anaerobic respiration of certain yeasts to create alcohol (see my second biology exam mindmap)
2. Alcohol

   Anmerkungen:

   • yum Examples that can be produced by fermentation for human consumption include beer and wineExamples of lethal alcohol include Methanol and PropanolReally all they are is an alkene with some oxygen attached

Anmerkungen:

• Ozone is O3 Broken down by CFC's Prevents harmful UV light from reaching the Earth CFCs are now banned due to the Montreal protocol

1. Permanent

   Anmerkungen:

   • caused by dissolved calcium sulphate
2. Temporary

   Anmerkungen:

   • caused by dissolved calcium hydrogencarbonate Can be thermally decomposed to remove hardness but this causes limescale
3. Removal methods

   Anmerkungen:

   • Ion Exchange and some Washing sodas are very good at getting out water hardness

1. Examples

   Anmerkungen:

   • Milk Cheese Butter
2. Difference

   Anmerkungen:

   • Fats are solid at room temperature Oils are liquid at room temperature
3. Esters

   Anmerkungen:

   • Carboxylic acid + alcohol=ester Fatty acids chemically joined to glycerol if it is more complicated
4. Fats in more detail

   Anmerkungen:

   • in saturated fats all the carbon-carbon bonds are single covalent bonds In unsaturated fats one or more of the carbon-carbon bonds are double covalent bonds

Anmerkungen:

• Hydrophilic head Hydrophobic tail

1. Cleaning
   1. Biological detergents

      Anmerkungen:

      • Enzymes digest the stains off of the material being washed
   2. Dry cleaning

      Anmerkungen:

      • Use of a solvent called tetrachloroethene Clothes are checked and things that may dissolve are removed Washed in a big washing machine