Chemistry

• remember to count every single bond in a molecule when asked to say the number of bonds even the double bonds or the OH bonds
• addition polymerisation creates only one product and condensation polymerisation must have two products as water is released
• one physical property that is used to determine if a substance is pure or impure is by using its boiling point and evaporating it to check if there’s substances inside
• remember to add the repeat unit squiggle for the structural formula of a polymer
• remember to draw a battery pack as one long line and then one short line with dots and label the terminals
• when talking about collision theory, remember to say that it is more/less particles per cm^3 and the rate of collisions is faster per second
• for a reaction with a cotton wool on top, the mass decreases due to the gas formed that escapes

  
• the water enters the condenser at the bottom and it leaves the condenser at the top

  
• this apparatus is called round bottom flask

  
• it is dangerous to heat alcohols with bunsen burners as they are flammable
• you can keep temperatures constant by using a water bath
• How do you separate oxygen from liquid air?

  fractional distillation
• How do you obtain water from aqueous sodium chloride?

  Distillation
• What is an element?

  A substance that can't be broken down into simpler substances
• What is an ion

  Contains different numbers of protons and electrons
• What is the change in oxidation number of iron in the reaction in the blast furnace

  Fe3+ -> 0
• Explain how oxidation numbers show something has been reduced

  Decrease in oxidation number
• What is the equation for limestone in a blast furnace?

  CaCO3 -> CaO + CO2
• What is the reaction of limestone in a blast furnace?

  Thermal decomposition
• What is the equation between limestone and sand?

  SiO2 + CaO -> CaSiO3
• What is the reaction between sand and carbon monoxide?

  CaSiO3
• What is the element (apart from carbon) that is mixed with iron to make stainless steel?

  Chromium/nickel
• What is the chemical name of rust?

  Hydrated iron (II) oxide
• What type of bond is relative molecular mass for?

  Covalent
• What type of bond is relative formula mass for?

  Ionic
• Why would one substance diffuse quicker than another?

  It has a lower relative atomic mass
• What catalyst is being used in a reaction between ethene and steam?


  Acid
• Remember it is butan-1-ol
• How do you tell if a solution is more concentrated?

  When a smaller volume is used there is a faster reaction, making it a faster reaction
• What is the advantage of using a measuring cylinder?


  It is easy to use and quick
• catalysts have to be transition metals
• oxidation numbers in compounds must equal to 0
• saturated solution - a solution containing the maximum of solute dissolved at a given temperature
• Describe how carbon monoxide is formed in the blast furnace


  reduction of CO2
• Symbol equation to show the reaction that occurs when Iron (III) oxide is converted to iron in the blast furnace


  Fe2O3 + 3CO -> 2Fe + 3CO2
• What is the reaction: CaCO3 -> CaO + CO2


  thermal decomposition
• What is the chemical name for SiO2


  silicon oxide
• Define covalent bond


  The sharing of a pair of electrons between 2 atoms
• What do all halides end with?


  -ide
• A halide compound that can detect the presence of water


  anhydrous cobalt chloride