Ocr f321 , f322 retakes on 27/05/16 and 10/06/16

Original post by Rust Cohle

HNO2. Question stated that it was not redox reaction therefore N could not have changed oxidation number meaning couldn't be HNO3

But isn't redox when both oxidation and reduction occurs? when it forms hno3, nitrogen is reduced/oxidised (can't remember) and everything else remains the same oxidation state?
But yes, you are correct cause i tried every possible combination and couldn't balance the equation with hno3, completely forgot about the possibility of an no2- ion

Reply 44

PeacefulSniper

Original post by PeacefulSniper

But isn't redox when both oxidation and reduction occurs? when it forms hno3, nitrogen is reduced/oxidised (can't remember) and everything else remains the same oxidation state?
But yes, you are correct cause i tried every possible combination and couldn't balance the equation with hno3, completely forgot about the possibility of an no2- ion

Ignore me, when something becomes reduced another thing has to become oxidised lol, stupid me.

Reply 45

Miminfl

Original post by Rust Cohle

Q: state the relative energies of 2s² and 2p6 orbital; also state relative energies of each 2p orbital. [2]

A: s orbital lower energy than p orbital; each p orbital has same energy level.

Defo got that wrong then , 😂

Reply 46

Pingu7

Original post by gracamole

everyone came out of the exam here complaining they found it difficult, but i dont understand why, that 5 mark question was a bit dodgy though but other than that I thought it was a much better paper than last year[/QUO

For me I revised all the hard stuff and did the hard past paper questions I forgot the simple and easy stuff and that paper had A LOT of simple formula questions and non of the hard topics. So I ended up finding that paper difficult. -____- guess I have to ace f322.

Reply 47

zirak46

What did everyone do for the dot andcross of Ca3P2? I did ionic bonding so 3 Ca2+ and 2 P3+
Someone told me there might be covalent bonding within the ionic maybe not sure

For the 5 marker, i put 2 tests
Add bromine to something chloride (turns orange)
Add bromine to calcium iodide (turns pink)
Shows rectivity decreases down group.
And then the ionic eq

What did people write for the galium ques?

I put ga3+

Think i put hno3 but answer must be hno2. Wish i recognised the n never reduced or oxidised

For the gases produced i put 1200cm3

For the grams of something thats 3sf i put 0.120 cause my answer was 0.1198

When others reply i'll put more answers up

Annoyed with orbital question.
I said s is lower than all p orbitals. But p orbital energy levels increase fromm1st to 3rd (im an idiot, all 3 are the same as someone mentioned to me after exam)

Also the ionisation energy/mp ques saying which elements to choose: i put N has lowest mp.. urghhhhh

Reply 48

PeacefulSniper

Original post by zirak46

What did everyone do for the dot andcross of Ca3P2? I did ionic bonding so 3 Ca2+ and 2 P3+
Someone told me there might be covalent bonding within the ionic maybe not sure

For the 5 marker, i put 2 tests
Add bromine to something chloride (turns orange)
Add bromine to calcium iodide (turns pink)
Shows rectivity decreases down group.
And then the ionic eq

What did people write for the galium ques?

I put ga3+

Think i put hno3 but answer must be hno2. Wish i recognised the n never reduced or oxidised

For the gases produced i put 1200cm3

For the grams of something thats 3sf i put 0.120 cause my answer was 0.1198

When others reply i'll put more answers up

Annoyed with orbital question.
I said s is lower than all p orbitals. But p orbital energy levels increase fromm1st to 3rd (im an idiot, all 3 are the same as someone mentioned to me after exam)

Also the ionisation energy/mp ques saying which elements to choose: i put N has lowest mp.. urghhhhh

I did ionic bonding between 3 Ca2+ and 1 double bonded p2 with 6- charge

AND ARGHH I put N too as i thought least electrons -> weakest van der waals

Reply 49

zirak46

Original post by PeacefulSniper

AND ARGHH I put N too as i thought least electrons -> weakest van der waals

YES OMG SAME FOR GOODNESS SAKE

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Reply 50

Original post by safhassan

guuuys how was it ... pretty good compared to last year. MaYBE after doin A2 that's why I find it easy. But I have to agree that, that 5 marker was dodgy. the rest was ok. Everyone got NaF for the one with the mr of 42.. I didn't get it. However if I did this paper last year I would've found it challenging. So what did everyone write about the s and p orbital thing.

I didn't get the NaF one. Also didn't get the dot and cross agh. Everything else was ok. What did you put for the highest melting point(?) and the fourth ionisation energy or something. I can't remember what the exact questions were haha

Reply 51

Original post by PeacefulSniper

Kicking myself for not remembering sf6 molecule's name, after exam checked the book and to my surprise... the name isn't even included! Also was the empirical formula of acid hno3? I'm guessing 60/60 for 90 ums eh

OCR are seriously so unhelpful in terms of revision guides. So many times they've asked stuff that isn't even mentioned! I got it on a guess but I'm sure you've picked up lots of marks elsewhere😀

Reply 52

What was the redox question in terms of electron transfer? I didnt check that at the end and feel like I wrote it the wrong way around grr

Reply 53

BanterBus

Original post by annaj97

What was the redox question in terms of electron transfer? I didnt check that at the end and feel like I wrote it the wrong way around grr

The metal solid you added lost 2 electrons (oxidised), the initial metal ion gained 2 electrons (reduced) back into a metal solid?

Reply 54

Original post by BanterBus

The metal solid you added lost 2 electrons (oxidised), the initial metal ion gained 2 electrons (reduced) back into a metal solid?

Do you remember the equation?

Reply 55

BanterBus

Original post by annaj97

Do you remember the equation?

Not fully sorry :frown:

All i remember is that there was a salt with 2- and 2+ ions, in which the 2+ metal ion was replaced by another metal. Someone will remember i'm sure! ^^

Reply 56

Original post by BanterBus

Not fully sorry :frown:

All i remember is that there was a salt with 2- and 2+ ions, in which the 2+ metal ion was replaced by another metal. Someone will remember i'm sure! ^^

No worries! I'm really hoping I wrote it the right way around as those were easy marks!

Reply 57

samherbs

I put the 5 marker:

Bromine with aqueous idione - turns purple as bromine displaces the ions.
Did the equation
Then put bromine with barium chloride - no reaction as it doesnt displace chlorine so no colour change.
Then put the reactivity decreases down the group.

Not too sure if correct :smile:

and for the last question i put 3x Ca2+ and 2x P3- with 3 electrons donated to the P from the Ca.

Reply 58

Lannew1

2

Made some stupid mistskes
Balanced an equation wrong, got the acid wrong and literally by accident but dipoler never t distomic hoping if im still in the 50's ill get an A?

Reply 59

BanterBus