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.
-
Re: OCR Chemistry F321 Exam. - [Next Tuesday[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(Original post by otrivine)
good question let me see could it be 104.5 ? it has to either 104.5 or 180 ? -
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




thats shocking how did they find out what is the structure like?i am sure there is a double bond between the oxygens ?
-
Re: OCR Chemistry F321 Exam. - [Next Tuesday[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(Original post by otrivine)





thats shocking how did they find out what is the structure like?i am sure there is a double bond between the oxygens ?
-
Re: OCR Chemistry F321 Exam. - [Next Tuesday[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?(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 -
Re: OCR Chemistry F321 Exam. - [Next Tuesday[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(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? -
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 -
Re: OCR Chemistry F321 Exam. - [Next Tuesday[how many orbitals? :3(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 -
Re: OCR Chemistry F321 Exam. - [Next Tuesday[1) do you want an equation with mg and water? or ionic you want(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
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 -
Re: OCR Chemistry F321 Exam. - [Next Tuesday[so what should i do for h2o2 if it comes up and what is the name pyramidal oh getting scared(Original post by Craming Revision)
how many orbitals? :3
-
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 -
Re: OCR Chemistry F321 Exam. - [Next Tuesday[It won't come up...(Original post by otrivine)
so what should i do for h2o2 if it comes up and what is the name pyramidal oh getting scared
-
Re: OCR Chemistry F321 Exam. - [Next Tuesday[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(Original post by otrivine)
so what should i do for h2o2 if it comes up and what is the name pyramidal oh getting scared
-
Re: OCR Chemistry F321 Exam. - [Next Tuesday[1) yeah, so Mg is oxidised, the equation for that. Then H2O is reduced, the equation for that. Doing the full equation helps.(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
2)correct.
3)say the same element is both ox and red, not the atom
4 and 5)sounds good. -
Re: OCR Chemistry F321 Exam. - [Next Tuesday[how did you get that it is 6 full orbitals?(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. -
Re: OCR Chemistry F321 Exam. - [Next Tuesday[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(Original post by Craming Revision)
how did you get that it is 6 full orbitals?