Chemistry edexcel C1 exam 14th may 2015

I put sodium chloride ?

It was table B because there was 50 + 19 in the middle and the volume was 25 + 25. this was 78 in 50 cm3
For tablet C it was 122 + somehing else to mae 164 and the volume was 50 + 50 which was 100.
Since, the volume is double you half the amount of tablet C to see how long it wil take to neutrilise the table and that turned out to b 82 (half 164).
Therefore tablet B takes less time to neutrilse the thing (i forgot what we were talking about ) so it was Tablet B.

For the 6 mark one, I jus mentioned properties (shorter and longer chains, boiling points, viscosity) and then said petrol was use in cars and bitumen for roads, how many marks would i get?

Hmm, I'd disagree. The question was asking about the tablet with the highest content of the active ingredient (the base) inside the antacid, not the antacid which acts the fastest, which can be influenced by factors like surface area etc. The two are completely separate things - the mass of the base and the speed of the reaction. As tablet C neutralised the highest amount of acid, it must have contained the greatest amount of the base. With excess acid, the amount of base is directly proportional to the volume of acid neutralised, surely? Say you had 50 cm3 of acid, and you had a whole tablet which weighed 50 cm3 and a whole tablet which weighed 30 cm3. The 50cm3 would contain the most base, correct? However, if you ground the 30cm3 tablet, the surface area would increase so it would act faster, but that doesn't mean that the amount of the base within it increases if that makes sense. So the 50cm3 tablet (tablet C) would still contain more base than the tablet which neutralised a less amount in a quicker time (tablet B) I could be completely wrong, but that's how I looked at it. At the end of the day, it's only a mark or two!

Yes it worked faster but the question was asking which is the most effective and tablet c neutralised 50cm3 wheras b neutralised only 25cm3

Lmao, yeah i get you but the antacid that has the highest active ingredient means that it takes less time to neutrilise and overall B took less time (my description excluded mass and all ).

Good and the polypropene multiple choice question was D?

I put water vapour condensed and fell as ocean and carbon dioxide dissolved into these oceans. Therefore water vapour levels decreased and carbon dioxide levels decreased. I think the last sentence is the bit that will get you the mark as it asks specifically about the composition. Just explaining that water vapour condensed isn't answering the question.

For the 6 marker on Bitumen/Petrol - It asked about properties and uses, but didn't say you had to link the property to the use so could you just essentially just list the properties and the uses? I put that petrol was a shorter chained, non-viscous fraction which was very flammable and so was good as a fuel in cars. It's low melting and boiling point means that it can easily change between a gas and a liquid in usage and storage/transportation. Idk if that's true or not XD For bitumen I just put it was used in tarmac and roofing, was a longer chained fraction, had a high mp and bp and was very viscous. How many marks do you think I may get?

the fact that you wrote about the structure was the key part of the question which would have got you 3-4 marks and the question didn't specifically say that you had to give examples but it is always good to write more in the 6 markers because it shows you know what your talking about. I don't think it will bring down your grade too much but i think you can get a solid 4 markers which is still very good

Lmao, yeah i get you but the antacid that has the highest active ingredient means that it takes less time to neutrilise and overall B took less time (my description excluded mass and all ).

Did everyone get 39.5g of air left after the reaction?


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For the first six mark questions I misread it and talked about petrol and bitumen? I explained their properties and uses instead in details and said the trend of the properties in the column
How many marks do you think that is worth ?


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Grade boundaries
48 A*
40 A
36 B