Unit 5 Applied Science Chemistry

• Al2O3 + 6HCI


  2A1 Cia+3H₂O
• Uses


  • Chromatography
  • Fulers pants, sunscreens and glass
  • Effective desiccant
• Bases


  A compound that reacts with and adds to form salt and water
• Metal salt + water

  What is formed when metal oxides react with acid?
• Used to make soaps and plastics. Used in food processing to peel fruit. Also found in drain and oven cleaner


  Give a use of sodium hydroxide
• 1. Crush the bauxite. React with NaOH at 170degrees. Filter mixture to remove solid impurities. Cool the mixture to form solid crystals of Al(OH)3. Heat in a calciner (kiln) at 1100degrees (calcination).

  Describe the Bayer Process
• Alumina and cryolite are placed in a steel tank lined with carbon (this is the cathode). Carbon anodes are placed in the solution. Aluminium ions are reduced to form molten aluminium which is then drained off.

  Describe the Hall-Heroult Process
• Extracting aluminium from alumina


  What is the Hall-Heroult Process used for?
• Separated by boiling point


  How are fractions separated in fractional distillation?
• At the bottom: larger hydrocarbons with higher boiling points

  At the top: smaller hydrocarbons with lower boiling points


  Describe the hydrocarbons that leave at the top of the column vs those that leave at the bottom
• Rutile


  What is the name of the ore that contains titanium dioxide?
• Titanium forms 'tree-like' crystals that affect the electrodes and the titanium ions can have side reactions that produce impurities


  Why do we not use electrolysis to extract titanium even though it has a similar reactivity to aluminium?
• Negative ion


  Define the term anion
• Positive ion


  Define the term cation
• A charged particle (something that has gained or lost an electron)


  Define the term ion
• When a less reactive metal is present


  When is hydrogen not produced during electrolysis of solutions
• When a group 7 element is present


  When is oxygen not produced during electrolysis of solutions
• H+ and Na+


  In electrolysis of brine what cations are present?
• O2- and Cl-


  In the electrolysis of brine what anions are present?
• Salt water


  What is brine?
• Diaphragm cell and membrane cell


  What are the two types of cell used in the electrolysis of brine?
• The diaphragm is place in the centre of the cell and is placed there to ensure hydrogen and chlorine gas cannot pass through, keeping the products separate


  In the diaphragm cell where is the diaphragm place and what is its purpose?
• Asbestos and polymers


  What is the diaphragm in the diaphragm cell made of?
• Polymers


  What is the membrane made from in brine electrolysis?
• D block


  In which block of the periodic table could you find the transition metals?
• They can lose different numbers of electrons forming numerous different metal compounds


  What is different about how transition metal ions form compared to other metals?
• A transition metal ion bonded to one or more ligands by dative covalent bonding


  Define the term complex ion
• Speed up a chemical reaction whilst remaining unchanged

  What is the purpose of a catalyst?
• Vanadium (V) oxide


  Which catalyst is used in the contact process?
• Iron


  Which catalyst is used in the Haber Process?
• By lowering the energy demands


  How does the use of iron in the Haber Process reduce environmental and financial cost
• Catalysts lower the activation energy of a reaction by providing an alternative route

  How does a catalyst speed up a reaction?
• Sulfur reacts with oxygen to produce sulfur dioxide. Sulfur dioxide is converted into sulfur trioxide in a reversible reaction. Sulfur trioxide is converted into sulfuric acid.


  Describe the stages of the contact process
• All bonds present in a molecule so it is clear to see how each atom joins to others


  What is shown by displayed formula?
• Show how the atoms are arranged but do not include the bonds


  What is shown by structural formulae?
• Simplified formulae with all hydrogen atoms removed and the carbon chain reduced to a line where the pointed ends represent a carbon atom


  What is shown by skeletal formulae?
• CnH2n+2


  What is the general formula for all alkanes?
• CnH2n


  What is the general formula for all alkenes?
• A family of organic compounds with the same functional group, but different length carbon chain. They will react in similar ways.

  What is a homologous series?
• Eth (i.e. ethane)


  What is the 'root' of a carbon chain containing two carbon atoms?