OCR F321 January 13th 2012 Draft Mark Scheme

Scroll to see replies

for the KI one at the start it said about the radioactive isotope, so I put it could contain that isotope?! is that a stupid answer? :')

Not sure on that one, perhaps a teacher could confirm.

Reply 21

james1234190

Original post by otrivine

Thanks

would they accept hydrogen as weak van der waals cause they are present in everything?

Again, not sure whether you had to put hydrogen bonds specifically, though you are correct.

Reply 22

james1234190

Original post by inspiredideas

i think h20 is an open latice because they asked specifically about ice

You could well be right, I am not 100% though.

Reply 23

james1234190

Original post by Dan12

for 4c) the Mr of potassium is 39.1 not 39.2 so I think the answer is 72.00 cm3

Good spot, corrected :smile:

Reply 24

otrivine

Original post by james1234190

Again, not sure whether you had to put hydrogen bonds specifically, though you are correct.

this paper was quite challenging there was lots of thinking needed cause hydrogen always has a high melting and boliling point? it says it in the ocr book as well?

Reply 25

james1234190

Original post by otrivine

this paper was quite challenging there was lots of thinking needed cause hydrogen always has a high melting and boliling point? it says it in the ocr book as well?

Hydrogen bonds are relatively strong compared to van der Waals and dipole - dipole intermolecular forces. Covalent / Ionic bonds are much, much stronger.

Reply 26

otrivine

[QUOTE="james1234190;35861606"]Hydrogen bonds are relatively strong compared to van der Waals and dipole - dipole intermolecular forces. Covalent / Ionic bonds are much, much stronger.[/QUOTE

BUT HOW LIKELY U THINK THEY WILL GIVE ME A MARK ON THAT? HOW DID U FIND THE EXAM

Reply 27

allwordsaredust

Wouldn't it be 107 for the bond angle, not 107.5?
Also, I don't think it's iodine is toxic - the question asked why do some countries use not use it, meaning that some still do so why would they if it were toxic?
The question started off mentioning how we need potassium so maybe the answer was some have potassium ions in their drinking water so they wouldn't need it?

Reply 28

otrivine

Original post by james1234190

Hydrogen bonds are relatively strong compared to van der Waals and dipole - dipole intermolecular forces. Covalent / Ionic bonds are much, much stronger.

how likely will they give me a mark and how did iu find the exam :wink:

Reply 29

kiko95

in question 1 they want to know what Relative isotopic mass is not atomic!!!!!!!!1111

Reply 30

allwordsaredust

Original post by alizasauras

Thank you for doing this :smile:

p.s I did dreadfully poor :frown:

Are you sure? Sometimes it seems worse then it is, and the markschemes can be anything from ridiculously strict to ridiculously allowing.
It was a hard exam.

Reply 31

kiko95

i think i flopped it aswelll lost probably 40 marks if not more

Reply 32

Paktriot

I hope the grade boundaries go down

Reply 33

kiko95

every jan its about 44-46 hope this jan it will be around 38-42

Reply 34

james20207

Original post by kiko95

every jan its about 44-46 hope this jan it will be around 38-42

Lets hope so! :smile:

Reply 35

james1234190

Original post by kiko95

in question 1 they want to know what Relative isotopic mass is not atomic!!!!!!!!1111

Thanks I was meant to say 'atom of an isotope' not just an atom :smile:

Reply 36

james1234190

Original post by otrivine

BUT HOW LIKELY U THINK THEY WILL GIVE ME A MARK ON THAT? HOW DID U FIND THE EXAM

I am not an examiner, marker or even a teacher so I cannot possibly say I am afraid. I found the exam challenging, but was fairly happy with how it went overall knowing that I nailed a few of the longer questions.