Chemistry

Chemistry

1. Separating Mixtures 1 and 2

   • dissolve- when it becomes part of it
   • solution-the mixture of a solute and solvent
   • solvent-able to dissolve other substances, water
   • solute- the thing being dissolved, salt
   • soluble-it is able to be dissolve
   • the melting/freezing point for water is 0 degrees
   • the boiling point for water is 100 degrees
   • boiling is when a liquid state turns into a gas state.
   • evaporating is when the liquid turns to gas due to change of temperature
   • distillation- can b used to purify water and separating two liquids
     • Steps of distillation
       • 1. the mixture of water and ethanol is heated till it boils.
       • 2. the ethanol turns inti a gas and moves up the flask
       • 3. the gas is cooled down until it turn into a liquid. this is called condensation
       • 4. the liquid ethanol drips out of the tube into a conical flask. this mixture is now distilled
     • the fractional distilled of crude oil.
       • oil is a thick black liquid that flows on water
       • the lower the substance is in the oil the higher their boiling point
       • gases-domestic uses
       • petrol- car fuel
       • Naphtha- petrol , white spirit
       • Kerosene- Jet fuel, paraffin
       • Gas oil- petrol,alkais
       • residue-lubricant waxes for ships
   • Chromatography
     • chromatography is another way out weather a liquid is a pure mixture of substances
       • the solvent carries the solute particles along as it flows over the filter paper. some solute particles aren't carried as far because they have less solubility
       • chromatography is the separation of different solutes based on different solubilities

2. Acids and Alkalis

   • An indicator indicates which substance are acids and which are alkalis
   • dark red- most acidic
     • vinegar
     • stomach acid
     • fizzy drinks
   • dark blue/purple- alkali
     • toothpaste
     • soap
     • shampoo
   • green netrual
     • water
   • neutralistion
     • when an acid reacts with an alkali, a neutralisation reaction occurs.
     • acid + alkali salt + water
     • measure out 25cm of sodium hydroxide, add 8 drops of universal indicator, add to acid until it turns green.
     • add one spatula of charcoal and boil the solution or a minute, filter and keep the filtrate, then boil the remaining of the solution, leave it for a day then salt crystals will be formed.
     • acid turns red litmus paper the same
       • alkali keeps blue litmus the same
     • acid turns blue litmus red
       • alkali keeps blue litmus same

3. Air and Gases

   • the air is mixture of many gases which include
     • nitrogen- 78 per cent
     • oxygen- 21 per cent
       • a spatula of maganese dioxide was placed in the conical flask. hydrogen peroxide was poured in slowly through the thistle funnel.
         • the splint should relight
     • CO2- 0.03
       • marble chips put in a continuously added to hydrochloric acid through a thistle funnel.then the gas collected in a condenser
         • bubble through lime water and it should turn cloudy
     • other gases- 1
   • Oxygen that form in the air is formed in the ozone layer. Ovygen is made from plant, algae, bacteria and other plants,which generates during photosynthesis.
   • hydrogen- Hydrochloric acid was poured into zinc slowly through a thistle funnel.
     • the splint should make a squeaky pop
   • Global warming
     • Humans affect global warming by not using renewable energy such as solar ,tidal , wave and wind . We keep using trees which take in all the carbon dioxide and increase oxygen
     • Global warming is when the climate slowly gets warmer. it could cause climate change or extreme weather conditions
     • stop burning fossil fuels, using renewable sources,planting more trees, public transport, saving energy, recycle