AQA Chemistry GCSE C1 Higher - Unofficial Mark Scheme Period.

There goes my a*

is this chemistry GCSE unit 1 higher 2015 paper?

why did you have to draw two lines that touch? so if they don't touch you'd lose marks?i just drew two lines going in opposite direction but i didn't make them touch, oops

Atomic structure

What is atomic number? (1 mark)

IT'S NUMBER OF ELECTRONS

PROTONS IS ON THE PERIODIC TABLE THEY GIVE, AND THERE WAS A SIMILAR QUESTION ON ANOTHER PAPER AND IT SAID DO NOT ACCEPT PROTONS IF I REMEMBER CORRECTLY

What is atomic mass? (1 mark)

Number of protons and electrons.

Why is there no overall charge? (2 marks)

Same number of protons and electrons, balancing the charges.

Why is Chlorine and Fluorine in the same group? (2 marks)

Because they both have 7 electrons in the outer shell.

Identify the element (1 mark)

Sulphur.

Metal and non metals reacting would form particles called ions (1 mark)
Non metals reacting would form particles called MOLECULES. (1 mark)

Limestone question

CALCIUM (1 mark) (I don't remember this question was it what is the main part of it or what else is in limestone, if the latter it is carbon?)

THERMAL DECOMPOSTION (1 mark)
Water. (1 mark)
ALKALI (1 mark).

Mortar&Aggregate

Draw 2 lines that touch. (2 marks)

Describe one way how they could improve the accuracy of the test? (2 mark)

Make sure the concrete beam have the same contact surface on one block with the other block, ensuring a fair test.

Force required for 0 grams of aggregate (2 marks)

Had to extend the line of best fit to 0, which is 44 newtons.

Why is his conclusion wrong? (3 marks)

Because the force did increase up until reaching 400 grams of aggregate, however after 400 grams of aggregate used the force decreased with the mass of 500, 600, 700.

Atmosphere

Explain why there are many theories involving how simple life were formed? (1 mark)

Because there's no conclusive evidence supporting one theory.

6 marker on the atmosphere

-Volcanic activity released carbon dioxide and also water vapour in the air, increasing levels of both in the early atmosphere.
-Earth cooled, decreasing levels of water vapour, and forming oceans.
-Carbon dioxide dissolves in the oceans, decreasing levels of carbon dioxide.
-Plant life do photosynthesis decreasing levels of carbon dioxide in the air and also increase levels of oxygen.

Metals and their uses

Why do we need to do stage 1 which is separation ? (2 marks)

Because separation of the ore, means that the ore would now be more concentrated of that metal and therefore allowing it to be more economical.

Why is cast iron not used for over head cables? (1 mark)

Too soft.

How is cast iron formed? (2 marks)

4% carbon in the cast iron reacts with oxygen at high temperatures, forming carbon dioxide.

Property of Aluminium (1 mark)

Low density

Transition metals and how can you tell copper is a transitional metal and not Aluminium. (3 marks?)

Aluminium is in group 3, and group 3 metals are not transitional metals. Copper is in the middle section of the periodic table where transitional metals are located.

Crude oil

Fractioning columns ( 4 marks)

Crude oil has a mixture of hydrocarbons.
Crude oil is vaporised.
Crude oil is condensed.
At different boiling points and collected.

Why is limestone suspension used and which environmental factor does it decrease? (3 marks)

Sulphur dioxide forming sulphuric acid reacting with the limestone, decreasing levels of sulphur dioxide in the air, DECREASING THE AMOUNT OF ACID RAIN

Finish cracking (1 mark)
C₂H₄

Polymerisation drawing (3 marks)

Removal of double bond.
Adding a bond on the brackets. -()-

Smart polymer property (1 mark)

MALLEBALE, STRONG, LIGHT (YOU ONLY NEED ONE)

Vegetable oils

Weird question poorly worded, since it was in reference for food and fuel.

Why are vegetable oils important? (1 mark)

Conservation of non renewable sources?

2 main stages (2 marks)

-Crushed
-Oil removed by pressing

One use of vegetable oil over than using water for cooking? (2 marks)

Vegetable oil has a higher boiling point than water, this means that the food will be cooked at high temperatures so making it quicker.

Emulsifier (4 marks)

-Hydrophilic head is attached to the water.
-Hydrophobic tail is attached to the oil.
-Stops separation of both liquids.

I've done a few corrections.

For the Limestone suspension question: isn't it true that the Carbon Dioxide passes through the Calcium Hydroxide producing Calcium Carbonate which can be disposed of preventing Carbon Dioxide gases being released into the atmosphere?

i got 34, do you think that will be a B?Also, I put 45 newtons, could that possibly be right?

It probably will be, as it's on the graph so there will be a 'allow' in the markscheme... eg. 'allow 35-45N'

i got 34, do you think that will be a B?Also, I put 45 newtons, could that possibly be right?

Most likely would be a B. I put 40 newtons, put 45 first than crossed it out.

Surely number of electrons = number of electrons? (although if it was on a markscheme i'm probably wrong xD)
'CALCIUM (1 mark)' - It was calcium carbonate


But good corrections

Oh yea? What's that Tim?

Not really, it was only one mark. Have confidence in yourself!

I messed up the ions and molecules, and still got about 50, so give or take a few marks, i'd have gotten 45-46. which is very close to an A*