Chemistry

• Metals Properties


  Strong

  Malleable

  Conductors

  High Melting Point

  High Boiling Point
• Transition Metals Properties


  Strong

  Dense

  Shiny

  Coloured

  Catalysts

  Conductors
• Alkali metals are very reactive because they easily lose their outermost electron to become positively charged ions (cations). This is why alkali metal compounds are ionic solids with high melting points.
• Electrolysis


  Electrolyte solution must be molten so that ions can move
• Anode - positive electrode where oxidation occurs
• The electrodes used depend on the type of compound being decomposed
• Cathode - negative electrode where reduction occurs
• Anion - negatively charged ion, moves towards the anode during electrolysis
• Cation - positively charged ion, moves towards the cathode during electrolysis
• Anode reaction: M → M2+ + e-
• Cathode reaction: M2+ + 2e- → M
• Reduction - gain electrons or loss of oxygen
• Electrolysis is the process of using electricity to decompose compounds into their constituent elements.
• In electrolysis, positive ions move towards the cathode (negative) while negative ions move towards the anode (positive).
• Oxidation - lose electrons or gain oxygen
• Extracting through Electrolysis


  At the negative electrode metals are produced due to metals positive charges attracting to the cathodes negative charge.

  At the positive electrode non metals are formed due the negative charges attracting to the anodes positive charge
• Electrolysis of Aqeous solutions

  Anode

  If OH‐ and halide ions are present cl, br and I forms

  Cathode

  If H+ ions and metals ions are present hydrogen gas will form If the metal is more reactive than hydrogen

  If metals are less reactive then metals form
• Titration

  1. Use the pipette and pipette filler to add 25 cm3 of alkali to a clean conical flask.
  2. Add a few drops of indicator and put the conical flask on a white tile.
  3. Fill the burette with acid and note the starting volume.
  4. Slowly add the acid from the burette to the alkali in the conical flask, swirling to mix.
  5. Stop adding the acid when the end-point is reached (when the indicator first permanently changes colour
  6. Note the final volume reading.
  7. Repeat steps 1 to 5 until you get concordant titres More accurate results are obtained if acid is added drop by drop near to the end-point.
• Making Salts


  1. Measure 20 cm3 sulfuric acid into a measuring cylinder and pour it into beaker

  2. Heat the acid gently using a Bunsen burner

  3. Add small amounts of insoluble base in this case copper oxide in excess (until no more reacts thus no more effervescence is produced)

  4. Filter using filter paper and funnel the solution to remove the excess copper oxide

  5. Pour the solution into the evaporating basin

  6. Evaporate the solution using a water bath until crystals start to form

  7. Leave the evaporating basin in a cool place for at least 24 hours

  8. Gently pat the crystals dry between two pieces of filter paper
• Group 1 Elements

  Alkali metals
• Reactions of Alkali Metals with Non-Metals

  1. Reaction with water

  2. Reaction with chlorine

  3. Reaction with oxygen
• Reaction with water

  • 2Na + 2H2O → 2NaOH + H2
• Reaction with chlorine

  1. Group 1 metals react vigorously when heated in chlorine gas to form white metal chloride salts

  2. As you go down the group, reactivity increases so the reaction with chlorine gets more vigorous
• Reaction with chlorine

  • 2Na + Cl2 → 2NaCl
• Reaction with oxygen

  1. Group 1 metals can react with oxygen to form a metal oxide

  2. Different types of oxide will form depending on the Group 1 metal
• Reaction with oxygen

  • Lithium forms lithium oxide (Li2O)
  • Sodium forms a mixture of sodium oxide (Na2O) and sodium peroxide (Na2O2)
  • Potassium forms a mixture of potassium peroxide (K2O2) and potassium superoxide (KO2)
• Group 1 Metals

  • Much more reactive than transition metals
  • Much less dense, strong and hard than transition metals
  • Have much lower melting points than transition metals
• Manganese melts at 2000 °C, sodium melts at 98 °C
• Group 7 Elements

  The halogens
• Halogens

  • They are all non-metals with coloured vapours
• Halogens

  • Fluorine
  • Chlorine
  • Bromine
  • Iodine
• Fluorine is a very reactive, poisonous yellow gas
• Chlorine is a fairly reactive, poisonous dense green gas
• Bromine is a dense, poisonous, red-brown volatile liquid
• Iodine is a dark grey crystalline solid or a purple vapour
• The halogens all exist as molecules which are pairs of atoms
• As you go down Group 7

  1. The halogens become less reactive

  2. Have higher melting and boiling points

  3. Have higher relative atomic masses
• All the Group 7 elements react in similar ways because they all have seven electrons in their outer shell
• Iodine will have a higher boiling point than chlorine

  As it's further down the group in the periodic table
• Group 7 elements

  • Fluorine
  • Chlorine
  • Bromine
  • Iodine