* Separate Chemistry

• transition metals have typical metal properties: relatively hard, strong, shiny and are malleable materials that conduct heat and electricity well.
• A catalyst speeds up the rate of reaction without being used up in the reaction.
• The compounds of transition metals are colourful. What colour they are depends on what transition metal ion they contain.

  
• Pure metals are malleable because they have a regular arrangement of identical atoms. The layers of ions can slide over each other.
• Alloys are made by adding another element to a metal.
• metals can corrode in the presence of oxygen and water to form their metal oxides. It is caused by redox reactions.
• You can prevent rusting by coating the iron with a barrier. This keeps out the water and oxygen.
• Electroplating is coating the surface of a metal with another metal using electrolysis.
• Titrations allow you to find out exactly how much acid is needed to neutralise a given quantity of alkali.
• method of titration: 1) measure out a set volume of the alkali into a flask. 2) add a few drops of indicator - usually phenolphthalein or methyl orange. 3) fill a burette with a standard solution of acid. 4) use the burette to add the acid to the alkali a little bit at a time, swirling regularly, until you think most of the alkali is neutralised. 5) the indicator will change colour when all of the alkali has been neutralised. 6) record the volume of the acid used to neutralise the alkali - also known as the titre. 7) repeat the process a few times and then calculate the mean.

  
• Concentration = number of moles / volume of solution
• percentage yield = actual yield / theoretical yield x 100
• Atom economy = total Mr of desired products / total Mr of all products x 100
• High atom economy is better for profits and the environment.
• The Haber process produces ammonia from nitrogen and hydrogen.
• the temperature, pressure and concentration of reactants affect how quickly the equilibrium is reached. if you increase the rate of reaction, you increase the rate at which you reach equilibrium.
• fertilisers help plants to grow. the three most important fertilisers are nitrogen, phosphorus and potassium. plants absorb these nutrients from the soil.
• ammonia can be reacted with oxygen and water in a series of reactions to make nitric acid.
• ammonium sulfate is a fertiliser you can make in the lab. you will need ammonia and dilute sulfuric acid. you can make this fertiliser by using this titration method.

  
• Molar volume = gas volume / number of moles
• one mole of any gas always occupies 24 dm3 at room temperature and pressure.
• Fuel cells use fuel and oxygen to produce electrical energy.
• advantages of Hydrogen-Oxygen Fuel Cells: they are more efficient than power stations or batteries at producing electricity, the electricity is generated directly from the reaction, there are fewer places for energy to be lost as heat, there are no moving parts so energy isn’t lost through friction, no greenhouse gases emitted, no nitrogen oxides, no sulfur dioxide + no carbon monoxide.
• Compounds Of some metals produce a characteristic colour when heated in a flame. Lithium ions, Li+, give a red flame. Sodium ions, Na+, give a yellow flame. Potassium ions, K+, give a lilac flame. Calcium ions, Ca2+, give an orange-red flame. Copper ions, Cu2+, give a blue-green flame.
• To work out whether a substance contains ammonium ions, all you need to do is add some sodium hydroxide solution to the substance and gently heat it.
• Test for Halide Ions using Silver Nitrate Solution. A chloride gives a white precipitate of sliver chloride. A bromide gives a cream precipitate of sliver bromide. An iodide gives a yellow precipitate of silver iodide.
• To test for carbonate ions in solution, add some dilute acid. If there are carbonate ions present, the mixture will fizz because the carbonate will react with the acid to produce carbon dioxide gas.
• to test for sulfate ions in solution, first add some dilute hydrochloric acid to the test sample. Then add some barium chloride solution. If there are sulfate ions in the solution, a white precipitate of barium sulfate will form.
• flame photometry is an instrumental method that allows you to identify ions in a dilute solution.

  
• flame photometry can also be used to identify different ions in a mixture.

  
• alkanes are saturated hydrocarbons. they are a homologous series of hydrocarbons - they contain just carbon and hydrogen atoms.

  
• Alkenes are unsaturated hydrocarbons. They are a homologous series of hydrocarbons with one C=C double bond.

  
• Alkanes and Alkenes burn in oxygen in combustion reactions. During complete combustion, they are oxidised to form carbon dioxide and water.
• Polymers are substances of high average relative molecular mass made by joining up lots of small repeating units called monomers.
• polyesters form when dicarboxylic acid monomers and diol monomers react together.

  
• DNA is a complex molecule that contains genetic information. It contains two strands and each strand Is made up of nucleotide monomers that bond together in a polymerisation reaction. DNA is made from four different monomers called nucleotides.
• Amino acid monomers form polymers known as proteins via condensation polymerisation. Proteins have many important uses in the human body.
• Carboydrates are molecules containing carbon, oxygen and hydrogen, used by living things to produce energy. Starch and cellulose are large, complex carbohydrates which are made up of many smaller units of carbohydrates known as sugars, joined together in a long chain.
• Plastics are a type of polymer which are made from crude oil.
• advantages of recycling polymers: reduces the amount of non-biodegradable waste filling up in landfill sites, reduces emissions of greenhouse and toxic gases, uses up less water and energy resources, reduces the amount of crude oil needed to produce more plastics, saves money + creates jobs.