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OCR B (Salters) F332 Tuesday 4th June 2013 Exam Discussion (Now Closed)

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I'm doing the Jan 2013 paper right now, and this is ridiculous, they've literally picked up questions WORD TO WORD, even calculations from the old spec past papers. I'm just sitting here going "are u kidding me"

Do you mean they have repeated old spec questions in new papers?! :redface:

Reply 261

nukethemaly

Original post by ambbs

Do you mean they have repeated old spec questions in new papers?! :redface:

Hahaha you sound happy. Yeah they have just a few though. I doubt they'd do it again especially during summer when more than half the country is doing it.

Reply 262

ambbs

Original post by nukethemaly

Hahaha you sound happy. Yeah they have just a few though. I doubt they'd do it again especially during summer when more than half the country is doing it.

It just surprised me that they actually did that! I suppose there's only so much content though that stuff's bound to be repeated (although right now during revision it feels like there's an endless amount of content!) Might glance over some of the old spec papers tomorrow then :smile:

Reply 263

krisshP

Original post by nukethemaly

I'm doing each paper twice and finishing these papers soon, then I'll go over some for a third time, then if there's time, I'll see the old spec ones, so I'm not there yet! Congrats, you finished a number of papers and so are in a good positions :wink:

Reply 264

krisshP

Can anybody explain how to do January 2013 q4ci please?

Reply 265

krisshP

WTF I opened a legacy zip file, opened a question paper and there's chemistry by design and chemistry of materials. Where's F332 legacy papers?

Reply 266

Branny101

Original post by krisshP

Can anybody explain how to do January 2013 q4ci please?

Awh krishhy mate :wink:

Posted from TSR Mobile

Reply 267

AGKhan

Why do instantaneous dipole-induced dipole forces strengthen when the atomic radius/electron shielding gets higher?

Posted from TSR Mobile

Reply 268

MintCrepz

Original post by AGKhan

Why do instantaneous dipole-induced dipole forces strengthen when the atomic radius/electron shielding gets higher?

Posted from TSR Mobile

As the atomic radius increases, the atom has more electrons (which causes the increase in radius). As a result of the atom having more electrons, it can produce stronger (more is not accepted in f332 mark schemes) intermolecular bonds (i.e instantaneous dipole-induced dipole forces). The same goes for electron shielding, as atomic radius and electron shielding increase with each other if you get me.

Reply 269

krisshP

Original post by nukethemaly

.....

Hey how do you know that ammonia NH3 is very soluble in water? Is it because N is highly electronegative, so N has a Delta - charge and H has a + and there's a lone pair on N, so hydrogen bond can form between water and ammonia NH3?

Thanks

Reply 270

MintCrepz

Original post by krisshP

NH₃is highly soluble in water because:

N is a small and highly electronegative atom causing partial charges on N and H
Ammonia contains a lone pair on the N, a condition required for hydrogen bonding
Therefore H bonds can be formed between ammonia and water so it is soluble

Reply 271

krisshP

Original post by MintCrepz

Thanks, I get it now :smile:

Reply 272

krisshP

Can somebody please explain how this reaction is propagation
N2O + O --> N2 + O2

How can it be a propagation reaction if there's just a radical on the reactants side? Isn't it termination?

Thanks

Reply 273

super121

Original post by krisshP

Can somebody please explain how this reaction is propagation
N2O + O --> N2 + O2

How can it be a propagation reaction if there's just a radical on the reactants side? Isn't it termination?

Thanks

It's termination if the reactants are radicals and react to form molecules.

Reply 274

krisshP

Original post by super121

It's termination if the reactants are radicals and react to form molecules.

So that reaction is termination right since O is a radical on reactants and no radicals form?

Reply 275

super121

Original post by krisshP

So that reaction is termination right since O is a radical on reactants and no radicals form?

It should be two radicals that react together :s-smilie:

Reply 276

nukethemaly

Original post by krisshP

Thanks, I get it now :smile:

Yeah exactly what Mint says. Just say that the lone pair on N allows the partially charged hydrogen to line up/bond with it

Reply 277

krisshP

Say if they say describe how hydrogen bonds form. Is this okay

Lone pair on oxygen attracted to hydrogen with a delta + charge.

I don't get what attracts what. Does the oxygen attract hydrogen? Or does the hydrogen attract oxygen? Or does hydrogen attract the lone pair on oxygen? Or what?

Thanks

Reply 278

nukethemaly

Original post by krisshP

It's the delta + charge on hydrogen that's strongly attracted to lone pair on O, F, or N

also, this will help clear everything up: http://www.chemguide.co.uk/atoms/bonding/hbond.html

Reply 279

krisshP

Original post by nukethemaly

It's the delta + charge on hydrogen that's strongly attracted to lone pair on O, F, or N

also, this will help clear everything up: http://www.chemguide.co.uk/atoms/bonding/hbond.html

Oh the hydrogen has a delta + and is attracted to the lone pair on oxygen.

Thanks

Btw it says in the spec that we have to know about batch and continuous production, but it had not come up on past papers. What do they want us to know about it an what even is batch and continuous? Advantages and disadvantages o each method?

Thanks