B (Salters) F331 (Chemistry for Life) 22nd May 2015 [Official Thread]

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Original post by KingdomOfTheLord

I meant the question about why Mendeleev (?) left a gap, hun. Ughhh I knew it was 4P2 but I thought it said configuration :frown:

(( It's so easy to lose marks in this paper, I think I've lost about 10-12 so far because of silly mistakes like not adding a minus :frown:

How'd you find it?

Thought it was a great paper :smile:

honestly don't worry you still have unit 2, plus many people are bound to make mistakes due to exam pressure

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Reply 201

Marli-Ruth

[QUOTE="f.loco;56114675"]Do I get 2marks for saying
Lime water goes cloudy as CO2 forms a precipitate (no named colour)

Posted from TSR Mobile[/QUOTE
Possibly although I think you would have had to say about the bubbles/fizzing since a gas is produced

Reply 202

Charlieboy101

For the observations of carbonates and lime water I also wrote that the calcium carbonate will be quicker to turn the water cloudy is this right?

Reply 203

-Gifted-

Original post by f.loco

Do I get 2marks for saying
Lime water goes cloudy as CO2 forms a precipitate (no named colour)

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I also said that for strontium carbonate gets cloudy slower because its more thermally stable- its probably the second mark.

Reply 204

KingdomOfTheLord

Original post by Marli-Ruth

Amount of lime water and amount of carbonate :smile:

wbu

I wrote mass of carbonate and volume of lime water too :smile:

My friend said that the carbonate wasn't solid though? It was right?

Reply 205

Adam971

Original post by Supergirlxxxxxx

That's only used in isomerisation to separate branches from unbranced

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Yeah that's what I thought, but I didn't know what else to put.

Reply 206

Supergirlxxxxxx

Original post by Charlieboy101

For the observations of carbonates and lime water I also wrote that the calcium carbonate will be quicker to turn the water cloudy is this right?

Yeah your right, with that question you'd say it turned Cloudy due to CO2 but CaCO3 would be more cloudy or take less time to turn cloudy because it is less stable

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Reply 207

KingdomOfTheLord

Original post by Supergirlxxxxxx

Thought it was a great paper :smile:

honestly don't worry you still have unit 2, plus many people are bound to make mistakes due to exam pressure

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Thanks for the motivation b xx I thought it was a lovely paper as well (thank the Lord), but afterwards I just realised my mistakes, would I get marks for talking about why the electrons repel in the bond angle q even if I got the angles themselves wrong?

Reply 208

Darcy1

Did anyone get 138.97 for the gas question? The way I did it was find the number of moles of the 2H2O2 whicu was 90/68 , then multiply it by 1.5 cos the reactant product ratio was 1:1.5 , then times it by 70 because 1 mole occupies 70dm3?

Reply 209

Marli-Ruth

Original post by -Gifted-

I also said that for strontium carbonate gets cloudy slower because its more thermally stable- its probably the second mark.

You could get the second mark by saying that but it said what would you SEE
I also put about it sr being slower

Reply 210

Charlieboy101

Also was the configuration 1s^2
2s^2 2p^6 3s^2 3p^6 3d^10 4p^4

Reply 211

Adam971

Original post by f.loco

Do I get 2marks for saying
Lime water goes cloudy as CO2 forms a precipitate (no named colour)

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1 mark I think because you mentioned the limewater colour change

Reply 212

Adam971

Original post by Marli-Ruth

Amount of lime water and amount of carbonate :smile:

wbu

Exactly the same, volume of limewater and mass of carbonate

Reply 213

Supergirlxxxxxx

Original post by KingdomOfTheLord

Lol aw it's okay! Everyone makes mistakes, your not alone :smile:

and yes even if the bond angle is wrong, for saying that the electron pairs repel as far apart as possible should get you the mark :smile:

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Reply 214

Ruuth

Original post by Adam971

Yeah that's what I thought, but I didn't know what else to put.

I put that it had a large surface area (used as a catalyst). I don't even know what I'm doing any more so I wouldn't trust that. I'm just failing one exam after the other

Reply 215

Adam971

Original post by Ruuth

I put that it had a large surface area (used as a catalyst). I don't even know what I'm doing any more so I wouldn't trust that. I'm just failing one exam after the other

That sounds better than my answer

Reply 216

Supergirlxxxxxx

Original post by Charlieboy101

Also was the configuration 1s^2
2s^2 2p^6 3s^2 3p^6 3d^10 4p^4

It didn't say to write the configuration out, it asked for the highest energy level, which is 4P2 but you'd still get a mark for it

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Reply 217

KingdomOfTheLord

Original post by Supergirlxxxxxx

Lol aw it's okay! Everyone makes mistakes, your not alone :smile:

and yes even if the bond angle is wrong, for saying that the electron pairs repel as far apart as possible should get you the mark :smile:

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Did you write that as well or...? Which q did you find the most difficult? I swear I was sitting there for about 3 mins trying to make sure an electron's mass was 0.0005
(Sorry I'm asking so much, I made my account like 5 mins ago, I usually just read these threads lol )