I had a wild guess with the question asking why was CO2 produced in the redox half equation, said O2 from the compound reacts with carbon...is that wrong?

Reply 2685

Croydon'Stepper

Original post by yarshad

Why is silicon dioxide *insoluble in water?

I said that it forms very strong covalent bonds in a giant covalent structure, so requires large amounts of energy to breakdown. Also said deltaG was positive.

Dunno how right I am tbh.

Reply 2686

Croydon'Stepper

Original post by Anshul91

I had a wild guess with the question asking why was CO2 produced in the redox half equation, said O2 from the compound reacts with carbon...is that wrong?

I have no idea. I said it uses electricity from the mains which is created using fossil fuels.

Reply 2687

erniiee

13

Original post by _jamie

I really hope they'll be okay with people using Cl- and CO32- etc

Hopefully they just meant no intermediates and will allow it.

I don't know why people are implying that they wouldn't accept CO32- and Cl- as even without the other ions these are the overall equations?

The reagent is Na2CO3, but the reaction is between the carbonate ion and the complex, the sodium ions/protons of HCl are just spectators.

Highly doubt there will be any marks lost for not showing them!

Original post by failingatm

Chemistry A-Level Failed? ☑

This

Reply 2688

wrnicholls

2

Original post by itssochaotic

omg you are kidding me, for the overall equations we had to write NaCo3???? and HCL??? SHOOOT.

Head of science at my school said they will accept the ionic equations.

Reply 2689

username1054067

2

Also,

About the ethane 1,2 diamine question when it said this is more likely to be produced due to the chelate effect?

I wrote about entropy? and that there were more moles of product than reactant? :F

Reply 2690

wrnicholls

2

Original post by Croydon'Stepper

I have no idea. I said it uses electricity from the mains which is created using fossil fuels.

So did I

Reply 2691

erniiee

13

Original post by Mocking_bird

Oh also, before the exam i heard a boy talking about "I hope cobalt as a catalyst comes up", and I have never heard about it! (neither had my classmates... seems like a fault on the teachers part im not sure).
So i was praying it didnt come up and well, it did :lol:

Drowning my sorrows in Maoms and crispy m&ms :lol:

Aha that question was tricky! Luckily it was in the June 12 paper (or something very similar) so I managed to work it out..this whole paper was horrendous though! Oh yea how did you find Bio?

Reply 2692

wrnicholls

2

Original post by yarshad

Also,

About the ethane 1,2 diamine question when it said this is more likely to be produced due to the chelate effect?

I wrote about entropy? and that there were more moles of product than reactant? :F

Yeah wrote that as well. I read it off a mark scheme last night.

Reply 2693

SuziieB

11

Guys I just calculated that I need 75 ums to get an A. What mark could that be??

(Please, be a C, please be a C...)

Posted from TSR Mobile

Reply 2694

Anshul91

Original post by yarshad

Also,

About the ethane 1,2 diamine question when it said this is more likely to be produced due to the chelate effect?

I wrote about entropy? and that there were more moles of product than reactant? :F

yeah its increase in entropy 3 moles to 7 or however many it was, as the complex formed is more thermodynamically stable.

Reply 2695

thuneh

Original post by yarshad

Why is silicon dioxide *insoluble in water?

>Giant covalent (macromolecular) structure
>Covalent bonds throughout
>A lot of energy required to break strong covalent bonds

That's what I wrote, or near enough anyway. Not sure if it's completely correct :/.

Reply 2696

MHay

If loads of people have written ionic equations they will probably accept it. The mark schemes are altered as they see what people write, so I presume that would be one that they would change into the mark scheme...

Reply 2697

Croydon'Stepper

Original post by yarshad

Also,

About the ethane 1,2 diamine question when it said this is more likely to be produced due to the chelate effect?

I wrote about entropy? and that there were more moles of product than reactant? :F

Yeah I wrote this aswell, I would've thought its right since past MSs have included this.

Reply 2698

MHay

Original post by yarshad

Also,

About the ethane 1,2 diamine question when it said this is more likely to be produced due to the chelate effect?

I wrote about entropy? and that there were more moles of product than reactant? :F