Chemistry Unit 2 Edexcel, Exam- 23rd May 2012

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I put both compounds decompose.

and the shape was tetrahedral.[please can you explain why it was tetrahedral I put trigonal pyramidal ? Thanks

Reply 1121

sylvestra45

Ammonia is set for long term use as it is made from raw materials that are constantly available.
It does-not have to be stored in high pressure as hydrogen

Reply 1122

Vocker

Original post by sylvestra45

Y is a tertiary carbocation.shape of molescule Y is trigonal planar,because it has three bond pairs.

i messed up on that question and started to write that it is a tertiary carbocation and why it is a carbocation. i didnt say anything about its a trignonal planar or anything of that. anyone think i might get like atleast a mark for that? :s-smilie:

what was the reason for the smell of NH3 being an advantage? i wrote its an advantage because you can detect from the smell that it is NH3......

Reply 1123

Ash03

[QUOTE="HARVEY123;37730733"]

Original post by solittletime

I put both compounds decompose.

and the shape was tetrahedral.[please can you explain why it was tetrahedral I put trigonal pyramidal ? Thanks

it was triagonal planar, because there were 3 bond pairs and no lone pairs, so they all repelled eachother to the position of maximum separation, 120 degrees apart.

what did people put for the multiple choice where it asked what happened to the distributions when temp was increased? (3rd multiple choice question)
I said it didnt change, because it said total area under the curve, and that's always the same...?

Reply 1124

solittletime

[QUOTE="HARVEY123;37730733"]

Original post by solittletime

I put both compounds decompose.

and the shape was tetrahedral.[please can you explain why it was tetrahedral I put trigonal pyramidal ? Thanks

No, I'm probably wrong. Someone has said the shape is trigonal planar..

Reply 1125

HARVEY123

Grade boundary prediction ?? I think 58/60 for an A
A

Reply 1126

sylvestra45

Calcium ion has a charge of (+2),whereas potassium ion has a charge of(+1).
Calcium ion is highly polarizing and can polarize nitrate To form stable CaO.
Calcium ion can easily distort the electron cloud of nitrate(anion).
(vice verse for potassium)

Reply 1127

sylvestra45

MCQ
activation
pie bond.

Reply 1128

sylvestra45

Probably I'll get 67/80 in this paper.

Reply 1129

solittletime

Original post by sylvestra45

MCQ
activation
pie bond.

The energy was activation? I wrote kinetic.

Reply 1130

mljones

Original post by sylvestra45

What was the question for this one?

Reply 1131

mljones

Does anyone remember what the question was after the ppm question?

Reply 1132

solittletime

What was the answer for the ppm question? I got 4 * 10-2 something

Reply 1133

117r

Original post by sylvestra45

MCQ
activation
pie bond.

Was it not sigma and pi bond? Or did I misread the question?

Reply 1134

solittletime

Original post by 117r

Was it not sigma and pi bond? Or did I misread the question?

I put sigma and pi bond aswell. The question was asking what bonds are in a double bond, right?

Reply 1135

cooldude101

I hated tthatt paper :frown:

Reply 1136

ShmangoBaby

Original post by sylvestra45

MCQ
activation
pie bond.

I'm pretty sure it's Kinetic Energy in the x-axis.
And the bond is 1 pi bond and 1 sigma bond.. :smile:

Reply 1137

ShmangoBaby

What did you guys get for the calculations ? (part B i think)
No. of moles and all that..

And also the equilibrium questions? What happens when pressure is increased etc..?