(Original post by MissGeek)
Hi everyone, I have made an attempt to make an unofficial mark scheme. I do apologise in advance if my answers aren't correct or if the questions are not in the correct order. Feel free to add anything which I may have missed
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
Which letter has 0.7? (1)
Y (I just guessed)
What conclusion can the scientists draw from the chromotagram about the sweets? (3)
Sweet S and P contain food colouring W and something. (can't exactly remember what I put in this question)
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. 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)
Reduction (Unsure about this)
Explain how molten and carbon dioxide is formed (I think it was the iron question, can't exactly remember) (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 steel is added. (1)
Pure iron is too soft for many uses
To make it harder
Explain why coins are now made out of nickel instead of something else? (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 sulfur dioxide and nitrogen oxide (1)
Acid rain (I think I may have got this wrong, it may be global dimming)
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.
Describe how plates are able to move. (3)
Heat is released from radioactive processes which causes convection currents in the mantles (Unsure if I got this right)
Describe fractional distillation, such as naptha (2)
Cracking occurs. Crude oil is heated to form a vapour it then passes over a catalyst. Naptha is heated to its boiling point, it then condenses.
I found this paper unusual, it was a bit different from other past papers, it required applied knowledge, but I hope I picked up on the easy marks. I don't know what the grade boundaries will be, but I certainly can't imagine them being really high, I don't see the grade boundary for an A* exceeding 75%