[krisshP]

(Original post by Chenice)
Explain why coins are now made out of nickel covered steel 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.

It could be ok to say:
As copper's supply of ores is low and copper is expensive

But I'm not fully sure.

[maxtate]

(Original post by krisshP)
It could be ok to say:
As copper's supply of ores is low and copper is expensive

But I'm not fully sure.

Yeah check on here it says what your saying but its not chemistry-based LOL

http://www.telegraph.co.uk/finance/p...-disaster.html

[micboy]

(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)
X

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)
3 elements

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)
Reduction

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)
Global dimming

Effect on SO2/NO2
Acid rain

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?

nickel plated steel coins used as they are cheaper to manufacture: "use steel rather than copper, which has surged in price over recent years. Making the cupronickel alloy is also a relatively expensive process. "

http://www.telegraph.co.uk/finance/p...-disaster.html

[micboy]

(Original post by maxtate)
Yeah check on here it says what your saying but its not chemistry-based LOL

http://www.telegraph.co.uk/finance/p...-disaster.html

lol DN, we posted at the same time.... =P

[maxtate]

(Original post by micboy)
lol DN, we posted at the same time.... =P

LOOL hey MZ

[rohin1204]

(Original post by krisshP)
It could be ok to say:
As copper's supply of ores is low and copper is expensive

But I'm not fully sure.

yh + copper is more useful being used for eg. wires & plumbing than as coinage

[clare1111]

Could you say that it's easier to copper plate and that copper is in low supply?

[MichelleQ]

Stop doing unofficial markschemes and ******** you're really embarrassing yourself. Don't be a low-life and keep your temper :P

[JJB21]

(Original post by tomaird)
what is the point in coming here just to be mean to people? I think you should leave this forum. At least Rohin1204 is helping people.

Yeah, he used a smiley face and everything

[daniya12]

(Original post by MissGeek)


Describe what happens when calcium oxide reacts with water. (2)
Calcium oxide reacts with water to form calcium hydroxide.

I think for this question you may have needed to mention something about heat, so this reaction is an exothermic reaction, which is why it warms the bean, because heat is given out

thanks for putting the unofficial markscheme draft up

[maxtate]

(Original post by daniya12)
I think for this question you may have needed to mention something about heat, so this reaction is an exothermic reaction, which is why it warms the bean, because heat is given out

thanks for putting the unofficial markscheme draft up

Oh yhh ur right I'll add it

[fasmeena99]

(Original post by elsher)
There was a questiona bout what enviromental impact does nitrogen,co2 etc cause.... i wrote Global Dimming. is that correct?

No,that's wrong...
CO2 causes global warming which is green house gas...
nitrogen causes acid rain n smog

[Jigglypuff786]

I reckon I got 100Ums for this exam, **** all the haters!! peace!!

[J_Choda]

I'm doing a mock for chemistry Unit 1 on monday! but i'm not sure if it's the old spec or new spec…could someone give me links to the June 2012 New Spec and Old Spec and their mark schemes Thanks…