(Original post by maxtate)
Draw a line of best fit on the petroleum - biodiesel graph. (1)
Smooth curved lined
Use the graph to help you explain the viscosity of the biodiesel and the petroleum (2)
The viscosity of the biodiesel decreases as the temperature increases.
The viscosity of the petroleum stays the same at all of the different temperatures.
Use the graph to suggest why petroleum is better than biodiesel (1)
Biodiesel's viscosity changes at different temperatures, but petroleum's viscosity remains the same.
Why are food colourings/additives added to sweets? (1)
The sweets taste better/better appearance
Which letter has 0.7? (1)
What conclusion can the scientists draw from the chromotagram about the sweets? (3)
Sweet S and P contain food colouring W and Y, which may have been the cause of the hyperactivity as they corresponded with the heights of the additives in the two sweets, showing they had equal solubility. However, in the sweets there were also some unknown substances, which could have been the cause of the hyperactivity.
How many elements does calcium carbonate contain? (1)
Explain why nitrogen and carbon dioxide come out of the kiln (3)
Calcium carbonate decomposes to from carbon dioxide, which is released. Carbon from methane is also reacted with the oxygen. Unreacted nitrogen from the air enters the kiln and then leaves the kiln.
Describe what happens when calcium oxide reacts with water. (2)
Calcium oxide reacts with water to form calcium hydroxide.
What method is used in the blast furnace (can't exactly remember) (1)
Explain how pure iron is formed from molten when you blast hot air in (2)
Carbon reacts with oxygen to form carbon dioxide. Carbon dioxide is then released.
Balance the equation of iron and carbon monoxide (2)
Correctly balanced equation.
Suggest why different elements are added to steel?. (1)
Because different alloys are required for different purposes.
Explain why coins are now made out of nickel instead of cupro-nickel (2)
The other coins used to be too soft, they had layers of atoms which slid over each other easily.
The new coins contain different sized atoms which don't slide over each other easily.
Desribe one of the effects of particulates (1)
Effect on SO2/NO2
Are biofuels 'carbon neutral'? Use information from the graph and your own knowledge to help you explain your answer (2)
Yes, biofuels release carbon dioxide, it is taken in by plants for photosynthesis. Also, the graph shows that biofuels release very little carbon dioxide (evidence from graph)
Describe how plates are able to move. (3)
Heat is released from radioactivity in the core which causes convection currents in the mantle
Describe fractional distillation, such as naptha (2)
The mixture of crude oil is vapourised and then cooled and condensed, and the different hydrocarbons are separated due to their boiling points, short chained at the top (cooler) long at the bottom (hotter)
Whats an ore?
Rock that has enough metal in order to make it worthwhile to extract.
Why do scientists have different theories bout soming?
Dunno whats goin on under Earths crust/new evidence coming up all the time
Diagram one mountain one- Cool to form crust, expanded so some parts protruded out.
Diagram two- Tectonic plates collide with high pressure exerting large forces pushing land upwards.
Bags or bottles? Advantages of bottles- Light/weatherproof, 35% can be recycled, abundant materials for manufacture, is usually reused 24 times
Disadvantages of bottles- Need 1600 degrees for making glass, so reaction uses lots of energy, landfill over long term
Advantage of milk bags- can hold up to 2 litres of milk, less packaging/polythene used, cheaper to make, less energy used to make it, less greenhouse gases/CO2 emissions
Disadvantages of milk bags- Plastic can split, lots of stages involved e.g. cracking distillation etc. so long time for manufacture, only 5% can be recycled, cant be reused often (landfill)
Any other questions?