chemistry paper 1

• ionic compounds have a lattic stucture
• ionic compounds have a strong electrostatic forces of atraction
• ionic compounds have a high melting and boiling point but dont conduct electricity
• covelent bonding is the sharing of electrons
• diamond which is a giant covelent stucture has 4 covalent bonds and are very ridgid
• graphite is a giant covalent structure has three covalent bonds between each carbon atom so one delocilised electron
• silicon dioxide is a giant covelent stucture of silicon and oxygen atoms
• nuestralisation reaction is

  acid + base =salt+water
• titration 


  fill the buiret with acid and the beaker with alkili and put indicator in it

  slowly put the acid in and mix until solution goes clear and measure how much acid was used to nuetrlise it
• a strong acid ionises completly in water and a weak acid only parcially ionises
• potasuim sodium lithium and calcuim are very reactive
• magnesium carbon zinc and iron are fairly reactive
• copper is not very reactive
• relitive formula mass =Ar*number of atoms in element *100

  Mr of compound
• moles =mass in g

  Mr
• in electrolysis the positive=cathode and the negative=anode
• in electrolysis with an aquas solution at the cathode h+ ions are present it will be produced if the metal is more reactive than h+ and at the anode OH- or halide ions they will be produced if not oxygen will be produced
• volume of gas=mass of gas *24

  mr of gas
• concentration = mass of moles of solute

  volume of solvent
• atom economy =relitive formula mass of solute

  relitive formula mass of all products
• percentage yeild =mass of product actualy made

  maximum therotical mass of product *100
• in the early 1800s elemets were arranged by atomic wieght and physicsl +chemical properties
• mendeleev left gaps and predicted new elements were going to be dicovered
• now the periodic table is laid out in increasing atomic number
• chromotoghy

  draw a line in pencil and put the ink on the line and place the bottom in the solvent and place a lid on the top the ink will seek up the paper and reveal all off the colours in it
• filterisation seperates insoluble solids from liquids
• evaperisation seperates soluble soilds from a solution heating it and it becoming cystilised
• distilation is used to seperate a liquid from a solution by evaporating and the condencing by sepration by them having diffrent boling points
• fractinal distilation is the same process as distilation but it will heat the diffrent liquids at diffrent times and do it over agian to get multipul diffrent liquids
• fullerenes forms spheres and tubes with hollow centres e.g the buchminster fullerene they are used to deliver drugs around the body and good catylists as they have large surface area
• metalic bonding is a very strong attraction between positive metal ions and delocalised electrons
• alloys are harder than pure metals
• nano particals are very small but have a very large surface area to volume ratio they are used as catylists and wound dressing but they are not well enough reschered on so people dont like using them because they dont know the effect to humans and the envirment
• metals and metal oxides are bases

  acid+metal oxide =salt+water
• acid = metal carbonate =salt+ water + co2
• you can make soluble salt out of insoluble bases 


  gently warm the dilute acid then slowly add the insoluble base until there is excess solid then cystilise the reaction to get the salt
• the formation of a metal ore is oxidation the loss of electrons and gain of oxygen
• extraction of metal is reduction the gain of electrons and loss of oxygen
• displacment is that thre more reactive metal will take the place of the less reactive metal e.g in iron+ copper sulfate =iron sulfate + copper iron loses 2 electrons and oxidises and and the copper gains 2 electrons
• group 1 elements are reactive and soft metals they all have one electron in the outer shell so they only need to loose one to become stabel the reactivity increases as the group goes down beacuse the outer shell is further away from the nucleus