yep, just think about that titration q in short answer, they asked citric acid which is a weak acid
by any other logic, other than 15 being A, equimolar citric and naoh should not have been added
mm yeh, however, a senior marker (that teaches at my school) says the answers in success one are "band 5 at best", i.e. I need further confirmation
I think I'll probably switch to Strontium-90 for Industry..
Chem will have something on radioisotopes for sure
on that note... does Americium 241 count as an Industrial radioisotope, after all, it's only used domestically.
Umm if E3 was 39/84
then E4 Raw minus E3 Raw is 15 marks
E3 = 75 reported
hence there is a one to one relationship between E3 cutoff, E4 cutoff and raw marks (only for this range, remembering that the difference is linear)
39/84 = 75
40/84 = 76
...
53/84 = 89
54/84 = 90
This is only...
the marks between bands are linear
so if 54/84 is the e4 cutoff (quite likely, i'd estimate cutoff at 54/84 this year) then
84 = 100
81 = 99
78 = 98
75 = 97
72 = 96
69 = 95
66 = 94
63 = 93
60 = 92
57 = 91
54 = 90
if you get a mark of say 59/84, that translates to 91.666666667 by this scale...
you should have accelerated =p
it was a little harder than 2010 but in saying that, this paper is not actually an 'epic hard' paper people make it out to be. 2006 was much harder