2016 IGCSE Chemistry Paper 2 Unofficial Mark Scheme 2016

Cuo+2HNO3----->H2O+Cu(NO3)2

?) HNO3 + CuO -> Cu(NO3)2 + H2O

It changes from red at 3.1 pH that is not slightly acidic that is very acidic. It shouldn't be accepted.

I wrote the same but there are people from my school which wrote oh instead of h20

unbalanced. must be 2HNO3

Ok these are the questions im worried about, can anyone tell me the right answers:
Which stage insoluble impurities are removed in calcium oxide-i put 3

How do u know its in excess-i put solid formed at bottom

Why cracking is important, i put bigger demand for short chains and short chains more useful

silicon wasn't an option

any other questions??

silicon wasn't an option

Why is cracking important? I wrote: Because the products obtained can be very useful.For example ethene can be hydrated to make ethanol and some other alkenes are reactive and can be used to make useful polymers.THAT DOESNOT MEAN THIS IS THE RIGHT ANSWER.

i saw on a mark scheme (cant remember which) that the reason for cracking to shorter chain was because shorter chain lengths are used for cars, which are in high demand

It defo was. Silicon is in period 3 and i chose it because an example of neutralisation is CaO reacting with SIO2. so it must be acidic.

From the table, the 'S' is the symbol for sulphur, Silicon would be Si

https://www.google.com/search?q=periodic+table&espv=2&biw=1492&bih=707&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiWu9yivKrNAhXMuhoKHbkhB2cQ_AUIBigB#imgrc=Hwj6WrltCUFUfM%3A


Si was also there.

It was my last exam for this year :P i have done bio, chemistry and maths in year 10 and going to do 5 other subjects next year (11).What subjects are left for you guys?

Physics paper 2, geography paper 3 and general studies paper 2. fun fun fun

they refuse orange. It's brown.