OCR Chemistry F321 Exam. - [Next Tuesday[

Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.

Announcements Posted on
Please change your TSR password 23-05-2013
IMPORTANT: You must wait until midnight (morning exams)/4.30AM (afternoon exams) to discuss Edexcel exams and until 1pm/6pm the following day for STEP and IB exams. Please read before posting, including for rules for practical and oral exams. 28-04-2013
Sign in to Reply
  1. TheFootyKing19's Avatar
    • Exalted and Worshipped Member
    • Location: Planet Earth
    • Posts: 1,232
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    What is the bond angle in H2O2?

    its either 180 or 104.5?
  2. Craming Revision's Avatar
    • Banned
    • Posts: 685
    • Warning points: 1010
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by otrivine)
    good question let me see could it be 104.5 ? it has to either 104.5 or 180 ?
    i read online but its defo not bent or linear they'r all sayin its 109* wtf is 109... lool pyramidal is 107 but thing is theres like 2 lone pairs on each oxygen :s
  3. otrivine's Avatar
    • TSR Legend
    • Posts: 14,747
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by TheFootyKing19)
    What is the bond angle in H2O2?

    its either 180 or 104.5?
    did u copy my answer?lool
  4. otrivine's Avatar
    • TSR Legend
    • Posts: 14,747
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by Craming Revision)
    i read online but its defo not bent or linear they'r all sayin its 109* wtf is 109... lool pyramidal is 107 but thing is theres like 2 lone pairs on each oxygen :s
    :eek::eek::eek::eek::eek::eek: thats shocking how did they find out what is the structure like?i am sure there is a double bond between the oxygens ?
  5. Craming Revision's Avatar
    • Banned
    • Posts: 685
    • Warning points: 1010
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by otrivine)
    :eek::eek::eek::eek::eek::eek: thats shocking how did they find out what is the structure like?i am sure there is a double bond between the oxygens ?
    if there were a double bond between the oxygens then there wouldnt be an electron for hydrogen to be bonded to as theres 2 pairs of electrons on each side of the oxygen even with the double oxygen bond
  6. otrivine's Avatar
    • TSR Legend
    • Posts: 14,747
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by Craming Revision)
    if there were a double bond between the oxygens then there wouldnt be an electron for hydrogen to be bonded to as theres 2 pairs of electrons on each side of the oxygen even with the double oxygen bond
    but 4 electrons sharing right with 2 oxygen and 2 electrons between oxygen and hydrogen and another 2 electrons between oxygen and hydrogen so makes it 8 electrons and full outer shell that why i thought its linear? but how can you tackle these types of question?
  7. Craming Revision's Avatar
    • Banned
    • Posts: 685
    • Warning points: 1010
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by otrivine)
    but 4 electrons sharing right with 2 oxygen and 2 electrons between oxygen and hydrogen and another 2 electrons between oxygen and hydrogen so makes it 8 electrons and full outer shell that why i thought its linear? but how can you tackle these types of question?
    seriously no clue lmao im predicted an a in chem in both unit 1 and 2 i dont get the bonding in h202 but thing is in jan 2012 paper i got the nh2h bonding right i cant seem to put my finger on h2o2... its cause nitrogen in nh2h is in group 3 so its -3 so it was easier to find out however o2 is in group 2 so it needs to gain 2 electrons and h needs to gain 1 electron x2 h x o = 2h 4o spare electrons. mhm so i rekon it would be a double electron in the middle of the bond. :3 still clueless lol it was in a paper in jan 2007 btw
  8. Pride's Avatar
    • TSR Demigod
    • Location: London
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    Happy revision everybody!

    Here's some:

    what are the ionic side equations for the reaction of Mg with water.

    how many full orbitals are there in aluminium (1s2 2s2 2p6 3s2 3p1) - think about it

    define disproportionation
    define a mole
    define electronegativity
  9. JuxtaposedJames's Avatar
    • Respected Member
    • Posts: 167
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    Has anyone got the jan 2012 paper?
  10. Craming Revision's Avatar
    • Banned
    • Posts: 685
    • Warning points: 1010
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by Pride)
    Happy revision everybody!

    Here's some:

    what are the ionic side equations for the reaction of Mg with water.

    how many full orbitals are there in aluminium (1s2 2s2 2p6 3s2 3p1) - think about it

    define disproportionation
    define a mole
    define electronegativity
    how many orbitals? :3
  11. otrivine's Avatar
    • TSR Legend
    • Posts: 14,747
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by Pride)
    Happy revision everybody!

    Here's some:

    what are the ionic side equations for the reaction of Mg with water.

    how many full orbitals are there in aluminium (1s2 2s2 2p6 3s2 3p1) - think about it

    define disproportionation
    define a mole
    define electronegativity
    1) do you want an equation with mg and water? or ionic you want
    2) is it 6?
    3) a redox reaction where an atom gets both oxidised and reduced
    4)Amount of substance contating many particles as there are carbon atoms in exactly 12 of carbon-12 atom#
    5) the measure of an atom to attract both of the electrons in a covalent bond
  12. otrivine's Avatar
    • TSR Legend
    • Posts: 14,747
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by Craming Revision)
    how many orbitals? :3
    so what should i do for h2o2 if it comes up and what is the name pyramidal oh getting scared
  13. TheFootyKing19's Avatar
    • Exalted and Worshipped Member
    • Location: Planet Earth
    • Posts: 1,232
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    Disproportionation - in which a chemical reaction where an element has been simultaneously reduced and oxidised.

    Mole - the amount of any substance containing as many particles as their are exactly carbons atoms in 12g of the carbon-12 isotope.

    Electronegativity - as the ability of an atom to attract the shaired pair of electrons in a covalent bond
  14. Pride's Avatar
    • TSR Demigod
    • Location: London
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by otrivine)
    so what should i do for h2o2 if it comes up and what is the name pyramidal oh getting scared
    It won't come up...
  15. TheFootyKing19's Avatar
    • Exalted and Worshipped Member
    • Location: Planet Earth
    • Posts: 1,232
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    I personally think the definition of RAM, Calculating RAM, Calculating Empirical Formula, drawing covalent and ionic structures and hydrogen bonding, defining salt, calculating moles/conc/volume, Redox reactions is a MUST on tomorrows paper
  16. TheFootyKing19's Avatar
    • Exalted and Worshipped Member
    • Location: Planet Earth
    • Posts: 1,232
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by otrivine)
    so what should i do for h2o2 if it comes up and what is the name pyramidal oh getting scared
    It's not on the syllabus - if a weird one does pop up then you can say electron pairs repel, lone pairs repel more and you will get 2 marks out of a possible 3/4
  17. Pride's Avatar
    • TSR Demigod
    • Location: London
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by otrivine)
    1) do you want an equation with mg and water? or ionic you want
    2) is it 6?
    3) a redox reaction where an atom gets both oxidised and reduced
    4)Amount of substance contating many particles as there are carbon atoms in exactly 12 of carbon-12 atom#
    5) the measure of an atom to attract both of the electrons in a covalent bond
    1) yeah, so Mg is oxidised, the equation for that. Then H2O is reduced, the equation for that. Doing the full equation helps.

    2)correct.
    3)say the same element is both ox and red, not the atom
    4 and 5)sounds good.
  18. Craming Revision's Avatar
    • Banned
    • Posts: 685
    • Warning points: 1010
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by Pride)
    1) yeah, so Mg is oxidised, the equation for that. Then H2O is reduced, the equation for that. Doing the full equation helps.

    2)correct.
    3)say the same element is both ox and red, not the atom
    4 and 5)sounds good.
    how did you get that it is 6 full orbitals?
  19. JuxtaposedJames's Avatar
    • Respected Member
    • Posts: 167
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
  20. Pride's Avatar
    • TSR Demigod
    • Location: London
    Re: OCR Chemistry F321 Exam. - [Next Tuesday[
    (Original post by Craming Revision)
    how did you get that it is 6 full orbitals?
    think about it. an orbital, is a region within an atom that can contain 2 electrons in opposite spin. In aluminium, there are 6 orbitals because 1s2, 2s2, 3s2, are all complete orbitals, and 2p6 is actually 3 orbitals, in one 'sub-shell'. similar question came up in jan 2012
Sign in to Reply
Share this discussion:  
Article updates
Moderators

We have a brilliant team of more than 60 volunteers looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Reputation gems:
The Reputation gems seen here indicate how well reputed the user is, red gem indicate negative reputation and green indicates a good rep.
Post rating score:
These scores show if a post has been positively or negatively rated by our members.