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Edexcel IAL Chemistry Unit 3 WCH03 May June 2016 Discussion

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Original post by ToxicPhantom007
I wrote something about cobalt chloride and i dont even remember :V


Yeah that is another test for water.
Original post by Hamadtype-
i got like 20.277 kj , I divided it by # of moles which is 0.0515625

got answer 393-


Yeah your mole number is correct I rounded that off to 0.0516 moles.But Energy is wrong.
Reply 82
Original post by don't cry-craft
You could also use anhydrous copper (ii) sulphate right?


Yes.
Original post by ToxicPhantom007
Anyways we still have unit 1 and 2. Best of luck everybody.
I also have Physics unit 3 tomorrow :frown:


I have physics too! But I can't stop thinking about the stupid mistakes I made on this test :/
Reply 84
Same exceot i wrote a beaker or a flask to collect the distillate
Reply 85
Original post by ToxicPhantom007
Anyways we still have unit 1 and 2. Best of luck everybody.
I also have Physics unit 3 tomorrow :frown:


Me too :redface:
Got any useful links?
guys for the value of c2h5 sth like this i got 1200 but i didnot the sign will this let me lose the mark even in the graph i didnot put the sign
Original post by OnTheHorizon
Yeah your mole number is correct I rounded that off to 0.0516 moles.But Energy is wrong.


I used 700-300 for water which is 400g then I plugged into the given equation...
Original post by don't cry-craft
What did you guys put about the bonds and the trend with the number of carbons and enthalpy change?


Was it something to do with the fact that as the number of carbons increase, more CO2 and H2O can be made, and bond making is exothermic etc..?
Original post by don't cry-craft
Was it something to do with the fact that as the number of carbons increase, more CO2 and H2O can be made, and bond making is exothermic etc..?


I wrote there will be more C-H and C-C bond energies which would increase the enthalpy change
Reply 90
Original post by don't cry-craft
I have physics too! But I can't stop thinking about the stupid mistakes I made on this test :/


I am supposed to be studying for unit 3 phy but I'm refreshing this page every 5 seconds. I made such silly mistakes I'm pulling out my hair :'(
Original post by a.adi1998
guys for the value of c2h5 sth like this i got 1200 but i didnot the sign will this let me lose the mark even in the graph i didnot put the sign


I'm not too sure about this. Maybe not as it is enthalpy change of combustion.
Reply 92
the condition should be heat and reflux
Original post by don't cry-craft
Was it something to do with the fact that as the number of carbons increase, more CO2 and H2O can be made, and bond making is exothermic etc..?


I wrote as no. of C atoms increases the more C-C and C-H bonds are there.Reacting it with O2 means more bonds will be broken so more energy is released.I wrote this because I believe you were supposed to explain the trends of the graph but using the equation given as reference.
Reply 94
For the haloalkane changing to alkene, I wrote alcoholic alkali for reagent and reflux heating for conditions. Will I get the reagent right, even though I didn't specify what type of alkali?
Original post by Blazyy
I am supposed to be studying for unit 3 phy but I'm refreshing this page every 5 seconds. I made such silly mistakes I'm pulling out my hair :'(


I know omg! I'm like slapping myself now. This was my first exam as well and this was not how I wanted it to go lol.
Original post by Hamadtype-
i got like 20.277 kj , I divided it by # of moles which is 0.0515625

got answer 393-


I can recall the expression that was given in the exam
Energy transferred = [(0.39 x mass of copper can) + ( 4.2 x mass of water)] x (temp change)
Mass of copper = 300 g
Mass of water = 400 g
Temp change = 12.1 C
So the answer comes to 21500 J somethin
Original post by I <3 WORK
For the haloalkane changing to alkene, I wrote alcoholic alkali for reagent and reflux heating for conditions. Will I get the reagent right, even though I didn't specify what type of alkali?



I feel like you might not. But then again, it depends on the mark scheme. That;s a dilemma for sure. For the condition I just put heating. Will that be enough?
Original post by ToxicPhantom007
What did you guys wrtie in that question in which we had to convert G TO F?
I wrote that reagent = potassium hydroxide
Condition = alcoholic


same but i think we missed out reflux
Original post by abz_98
the condition should be heat and reflux


Will heating be enough?

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