Chemistry

• water turns anhydrous copper sulfate from white to blue
• test for unsaturated hydrocarbon: bromine water, decolorizes (colourless gas)
• cracking: process of breaking long chained alkene into shorter alkane and alkene
• conditions needed for cracking: high temp and catalyst
• homologous series: family of organic compound with similar chemical properties due to presence of the same functional group
• hydrocarbons are organic compounds containing hydrogen and carbon only
• lead causes brain damage
• nitrates and phosphates lead to eutrophication
• chlorine is used to kill microbes/bacteria in water
• argon is used in light bulbs
• ionic compounds conduct electricity when molten or in aqueous solution because their ions are free to move and carry electric current
• methyl orange is red in acidic solution and yellow in alkaline
• thymolphalein is colourless in acidic and blue in alkaline
• sodium = yellow flame

  potassium = lilac flame

  copper = blue-green flame

  Lithium = red flame

  Calcium = orange-red flame

  Barium = light green flame
• metals are : sonorous, have high m.p and b.p, high density, shiny
• alloys are stronger and harder and better resistant to corrosion than pure metals
• brass is a mixture of copper and zinc
• raw materials added to furnace are: iron ore, coke and limestone
• exothermic graph: energy of reactants is more than energy of products
• factors affecting rate of reaction: size of particles, temp, concentration
• water used as solvent or coolant (industrial use)
• gas released from decomposition and digestion in farm animals is methane gas.
• refinery gas used in domestic use
• gasoline is used for fuel for cars
• naphtha is used in making chemicals
• kerosene is used in making fuel for jets
• diesel is used for making fuels for trucks
• fuel oil is used for fuel in ships
• lubricating oil is used for lubricants and waxes
• bitumen is used in making roads
• alkanes are used as fuels + they are unreactive and saturated
• alkenes are not used as fuels + they are reactive and unsaturated
• polymers are large molecules built up of small repeated units of monomers
• nylon and terylene are used in making clothes, ropes and bags
• diamond and graphite have very high melting points because they are very strong covalent bonds
• oxidation is gain of oxygen
• reduction is loss of oxygen
• alkali metals are soft, shiny when cut

  their melting and boiling point decreases as we go down the group

  their reactivity increases as we go down the group
• helium is used to make hot air balloons rather than hydrogen because it is less dense and less flammable
• gases that do not react with acid are passed through concentrated sulfuric acid to be dried