Pls Help !! Chemistry paper 3 ???

[XxMarkxX]

guys , anyone know how sugar is changed to ethanol ???

 

[PUSHPAK1321]

Fermentation
yeast
gulcose=======> ethanol+carbondioxide

 

[Outofideaz]

i need help plzz in the following two questions !!!

 

[CaptainDanger]

Are these IGCSE questions????

 

[Keeemoman]

Are these IGCSE questions????

Nop it isnt IGCSE questions

 

[Outofideaz]

yeah their ig questions from past papers .. plz help ... i can prove dey r if u want

 

[HyDraZin3]

Give me the link plz....

 

[Keeemoman]

i need help plzz in the following two questions !!!

Give the marking scheme so that I can give you the answer :wink: :wink: :wink: :wink:

 

[smartygirl]

SO GUYZ DO U RILLI THINK CHEM WILL B AS HARD AS PHY N BIO
I THINK SO

 

[Keeemoman]

SO GUYZ DO U RILLI THINK CHEM WILL B AS HARD AS PHY N BIO
I THINK SO

U mean varient 1, if varient 1 it will be damn easy in order to balance it but for varient 2 damn hard also to belance it

 

[CaptainDanger]

yeah their ig questions from past papers .. plz help ... i can prove dey r if u want

These are tough... Or are they older papers????

 

[Keeemoman]

Ok I dont need the proof I just need the answer paper to make sure my answer

 

[xIshtar]

For the first one:

d.i) 1 mole takes up 24dm^3, so 5 moles were formed.
ii) If 5 moles were formed, then using the second equation, (EDIT) As the question says that 1 mole was formed, y=2.
iii) I have no idea how to find x.


For the second one:

a) Energy Saved = 250 x 95/100 =237.5

This implies that 12.5 GJ is used to make 1 tonne of paper via recycling.. (I think so anyway )

These questions are pretty tough, so I'm just trying my best, I hope I somewhat helped and somewhat got it right.

 

[Keeemoman]

I think this is my answer for te first one
But for second I didnt read it

 

[Outofideaz]

thanks ur answer is correct according to the marking scheme ... one question is frm 1993 and the other frm 1994

 

[HyDraZin3]

In mark scheme is is written y=2 and x= 5-2=3

 

[xIshtar]

In mark scheme is is written y=2 and x= 5-2=3

You sure, where did you find the ms?

 

[HyDraZin3]

yaa, i am sure and xishtar check ur pm plz... 8)

 

[xIshtar]

Ahh, I think I know how to find x too. If 1 mole reacts to form 1 mole of CO2, then 3 + x = 5
=> x = 2.