Ocr f321 23 may 2013~official discussion thread

I put the litmus paper turned red because of the HClO (Chloric acid) AND the HCL

i guess they would ignore HCLO and give mark,but if markschemes hard and examiner decides to mark first attempt well..

H20 + Cl2 -> HClO + HCL

thats the equation for sure it was in past paper,
now HCL is acid and is made therefore the paper is red

I went through this paper just now with my chemistry teacher and he said that a lot of thinking was required to answer these questions - meaning they weren't obvious at all.

Most people at my college found it hard and there seems to be mixed views on here but usually (and unfortunately) the grade boundaries are higher in the summer exam period.

I think this paper was so different to the past paper questions - I felt there was more to do for little marks. E.g. the volume question required more time, however, it was 1 mark which is meant to equal 1 minute.

What does everyone think grade boundary wise? I feel it was harder than January.

The question referring to table 5.1 I think it was, with a range of ionisation energies. It asked why is it unnecessary to differentiate between Diamond & Graphite when referring to I.E of Carbon, or something along the lines of that. I presumed that, allotropes (different physical arrangement of the same element) have the same ionisation energy, anyone mind shedding some light on this question?

Chloric Acid should be a mark though as its acidic

Diamond and Graphite are both pure carbon. For the first ionisation energy then you need one mole of gaseous atoms and as diamond and graphite in their gaseous states are both just the same (pure carbon) then there is quite literally no difference between their first ionisation levels, as they are the same thing!

What were the common errors pointed out do you remember?

Ah someone mentioned this, I guess if you said their ionisation energies are equal you'll get the mark, or you may have to reference to the fact that they are gaseous - hopefully the examiners provide some leeway.

its not 360cm3, its 1080cm3 because you have to take into account the 1:3 molar ratio

I went through this paper just now with my chemistry teacher and he said that a lot of thinking was required to answer these questions - meaning they weren't obvious at all.

Most people at my college found it hard and there seems to be mixed views on here but usually (and unfortunately) the grade boundaries are higher in the summer exam period.

I think this paper was so different to the past paper questions - I felt there was more to do for little marks. E.g. the volume question required more time, however, it was 1 mark which is meant to equal 1 minute.

What does everyone think grade boundary wise? I feel it was harder than January.

where was this 1:3 molar ratio??

Inferred this in the question anyway I think, so I don't think you will (sorry!).

I'd say the fact that they're gaseous and made up of the same atom's would be one mark (working off an F325 marking mindset).

I think you got it wrong? Sorry It actually said in the question that the litmus paper turned red :')


Posted from TSR Mobile

Bugger, thanks for the clarification.