OCR AS Salters Chemistry F332 - Wednesday 23rd May 2012 1:30pm

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the first is correct, but they gave two marks because the second is also correct. however, the first is "more" right because one of the electrons in the 4s sub-shell is actually in the 3d sub-shell.

It is more stable with either full or half full d-sub shell. A full d-shell is 10, whereas copper has 9 in it. So, one electron from the 4s shell is "promoted" to the 3d shell, so copper has 3d10.

BTW- chromium does the same

Oh right, fair enough

Thank you :smile:

Reply 381

matty b

Original post by chrisduck

Does anyone know what the systematic name of the product in the first equation in the advance notice? The one that doesn't get produced.
Thanks

It is propiophenone, or 1-phenylpropan-1-one, and is liquid at the temperature stated in the reaction

(edited 11 years ago)

Reply 382

dongonaeatu

How is the chlorines oxidation state +4 in 4cl02?

or simple cl02? i thought o2 was -2? so shouldn't cl be +2? but in the mark scheme it says cl is +4.

(edited 11 years ago)

Reply 383

Tikara

Has anyone got the spec? (please :smile:

)

Reply 384

chrisduck

Original post by matty b

It is propiophenone, or 1-phenylpropan-1-one

Thanks. I just did a lot of googling and asking people, pretty sure its 1-phenylpropan-1-one :biggrin:

best come up now aha

Reply 385

M_Wigley

Original post by dongonaeatu

How is the chlorines oxidation state +4 in 4cl02?

or simple cl02? i thought o2 was -2? so shouldn't cl be +2? but in the mark scheme it says cl is +4.

It is not O2 that is -2 it is just O that is -2. Therefore 2 x O = -4 so the Cl must be +4 :smile:

Reply 386

holly90210

Original post by dongonaeatu

How is the chlorines oxidation state +4 in 4cl02?

or simple cl02? i thought o2 was -2? so shouldn't cl be +2? but in the mark scheme it says cl is +4.

the oxygen is minus 2 but because there's two of them it becomes -4 so the chlorine must become +4 to make sure the molecule has no overall charge :smile:

Reply 387

matty b

Original post by dongonaeatu

How is the chlorines oxidation state +4 in 4cl02?

or simple cl02? i thought o2 was -2? so shouldn't cl be +2? but in the mark scheme it says cl is +4.

o (ie the atom in a compound) is -2.

Reply 388

dongonaeatu

Original post by M_Wigley

It is not O2 that is -2 it is just O that is -2. Therefore 2 x O = -4 so the Cl must be +4 :smile:

Original post by holly90210

the oxygen is minus 2 but because there's two of them it becomes -4 so the chlorine must become +4 to make sure the molecule has no overall charge :smile:

Original post by matty b

o (ie the atom in a compound) is -2.

Thank you

Reply 389

Kreayshawn

do we need to know when the oxidation states of H and O are different to regular? (+1 and -2)

Reply 390

Chandz94

Whats the difference between homolytic fission and photodissociation?

Reply 391

twizzzzzzter

Original post by Chandz94

Whats the difference between homolytic fission and photodissociation?

homolytic fission is the breaking of a bond forming a pair of radicals. photodissociation is the just the general breaking down of a molecule with h.v.

Reply 392

Chandz94

Original post by twizzzzzzter

homolytic fission is the breaking of a bond forming a pair of radicals. photodissociation is the just the general breaking down of a molecule with h.v.

Ah thanks! but some mark schemes dont allow photodissociation but some papers did, how would you know whether to write homolytic fission or photodissociation?

Reply 393

Tikara

Are all halogens poisonous/toxic? or do we just need to know which are? (in just as gases eg. Cl2 F2 etc.)

Reply 394

Kreayshawn

Original post by Chandz94

Ah thanks! but some mark schemes dont allow photodissociation but some papers did, how would you know whether to write homolytic fission or photodissociation?

i would talk about photodissociation when referring to ozone formation and homolytic fission when talking about halogenoalkanes

Reply 395

dongonaeatu

Give the outer sub-shell structure of an iodide ion

the answer is 5p6

what would be a quick way of working this out?

Reply 396

dongonaeatu

And is methanal an aldehyde?

Reply 397

physicsnut

Original post by Kreayshawn

in june 2011 you needed 172 marks total to get an A, so back then you would need around 76 marks, but it all depends on the grade boundaries. aim for about 80 i'd say

it doesnt work like that because F331 and the CIPs are weighted differently, 20% CIP 30% F331

Reply 398

chrisduck

Original post by dongonaeatu

Give the outer sub-shell structure of an iodide ion

the answer is 5p6

what would be a quick way of working this out?

Use the periodic table, google it. Too hard to explain on here. But it is simple. http://www.chemguide.co.uk/atoms/properties/elstructs.html

Basically it is in period 5, in the p group =5p and if you count along from the start of the p group (period 3) it is = 5p5 (In=1, Sn=2, Sb=3, Te=4, I=5,Xe=6) + one for the ion charge = 5p6

(edited 11 years ago)

Reply 399

Roshniroxy

Original post by Tikara

Are all halogens poisonous/toxic? or do we just need to know which are? (in just as gases eg. Cl2 F2 etc.)

Not all are poisonous or toxic. Learn their individual properties, dangers and uses. Here I'll list them out to you:

Fluorine= Used in toothpaste, in water and refrigerants. Highly reactive.
Chlorine= Toxic when a gas, used for water treatment, to make bleaches and PVC
Bromine= Corrosive to skin, used to make agricultural fumigants, flame retardants and used into camera film (silver-bromide) as it is light sensitive.
Iodine= Due to not being at a gaseous state on its own, it's highly unlikely it'll form a toxic gas. It is used to make medicines and it is in salt.

Hence they're toxic in their gaseous states and this applies to chlorine specifically, bromine is also but after doing some research I've concluded that iodine is corrosive as a vapour and not toxic