POST YOUR BIO AND CHEM PAPER 1 DOUBT HERE !!!!

[Razo513]

Consider the equation where
The more reactive halogen displaces the less reactive one.Since,iodine is nearly the least reactive so it can't displace any halogen ,except At which is rarely used,..
So X2 is Chlorine..
Consider chlorine is passed through aqueous potassium iodide,the result will be potassium chloride and iodine(in solution)..
Potassium iodide is colourless and iodine solution is yellow brown.

oh ok thx

 

[natsume hyuga]

would I have to study the whole syllabus again?

you know what, other than the past papers i think u have to go through the basics all over again. I dont think itll be that bad because we recently had the exam, and if u studied well for that then great.

 

[L-Girl]

you know what, other than the past papers i think u have to go through the basics all over again. I dont think itll be that bad because we recently had the exam, and if u studied well for that then great.

thanks! i'll do that

 

[MERIHAN]

what is the difference b/w the two question ? i means the statement "until the green leaves have appeared above the soil " means same as "until the seedling start to photosynthesize " ISNT'D ??? THEN WHY ANSWERS DIFFERENT ???

THANKS IN ADVANCE !!

 

[Skynox]

View attachment 12073

what is the difference b/w the two question ? i means the statement "until the green leaves have appeared above the soil " means same as "until the seedling start to photosynthesize " ISNT'D ??? THEN WHY ANSWERS DIFFERENT ???

THANKS IN ADVANCE !!

One is against drymass,the other is against number of cells.During germination the number of cells keep increasing and never decrease so the graph is "c"..
The drymass during germination:
Mass decrease due to the breakdown of starch reserves present in the cotyledons, then starts to increase as the plant photosynthesisze.

 

[Razo513]

View attachment 12073

what is the difference b/w the two question ? i means the statement "until the green leaves have appeared above the soil " means same as "until the seedling start to photosynthesize " ISNT'D ??? THEN WHY ANSWERS DIFFERENT ???

THANKS IN ADVANCE !!

difference in Y axis

 

[saroooor]

I Have a question plz , november 05 number 19 Chemistry is it solid because they are insoluble ?

 

[natsume hyuga]

whats the reasoning behind this?

 

[natsume hyuga]

I Have a question plz , november 05 number 19 Chemistry is it solid because they are insoluble ?

yea

 

[saroooor]

One is against drymass,the other is against number of cells.During germination the number of cells keep increasing and never decrease so the graph is "c"..
The drymass during germination:
Mass decrease due to the breakdown of starch reserves present in the cotyledons, then starts to increase as the plant photosynthesisze.

Thanks A lot !

 

[natsume hyuga]

this one too please

 

[L-Girl]

this one too please

well try to balance the equation with the 4 choices.. you'll find that it only works with A

 

[Razo513]

this one too please

u can do this as follows : 8 O2 molecules required so
X + 8O2 ---> H2O +CO2
then u try each compound & see when does the 2 sides balance u get : C6H9OH +8O2 --> 6CO2 + 5H2O

 

[L-Girl]

http://www.dailymail.co.uk/news/art...-Expect-fewer-exam-passes-parents-warned.html

and that is....?

 

[fishcook]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s10_qp_13.pdf
Q20.. why is it D?
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s11_qp_11.pdf
Q19.. why is it B?

 

[MERIHAN]

One is against drymass,the other is against number of cells.During germination the number of cells keep increasing and never decrease so the graph is "c"..
The drymass during germination:
Mass decrease due to the breakdown of starch reserves present in the cotyledons, then starts to increase as the plant photosynthesisze.

THANK YOU SOOO MUCH

 

[Razo513]

whats the reasoning behind this?

ok for some reasoning in this .. first endothermic reactions dont show increase in temp so u eliminate all the answers with increase at the beginning .. u will have 2 choices now when one of the reactants is halved ( in this case the water fro 1000cm3 to 500cm3 ) then there will be a more decrease in temp shown this decrease will be double/twice that of the 1000 cm3 .. be careful only one of the reactants is changed the other remains constant .. therefore when the volume of water is halved the temp decrease is double (10 * 2 = 20 degrees decreased)

 

[fishcook]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s10_qp_13.pdf
Q20.. why is it D?
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s11_qp_11.pdf
Q19.. why is it B?

 

[Skynox]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s10_qp_13.pdf
Q20.. why is it D?
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s11_qp_11.pdf
Q19.. why is it B?

YOu filter to remove the excess solid then concentrate the solution to get a saturated one then you filter to obtain crystals and heat to dry.
A solution means that both salts should be soluble since insoluble salts don't split up into ions.
Since silver chloride is insoluble,barium sulfate is insoluble so the only anion left is the nitrate..

 

[fishcook]

YOu filter to remove the excess solid then concentrate the solution to get a saturated one then you filter to obtain crystals and heat to dry.
A solution means that both salts should be soluble since insoluble salts don't split up into ions.
Since silver chloride is insoluble,barium sulfate is insoluble so the only anion left is the nitrate..

but dont silver chloride still contain chloride ions and same thing goes for barium ions in barium sulphate?