IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => IGCSE/ GCSE => Sciences => Topic started by: godfather93 on May 08, 2009, 03:06:07 pm
-
can someone please answer the question. the paper is attached.
Q2 c)
-
WTF.....?
Its Chemistry...
Srry, I'm in the commerce stream :D (Accounting, Business St. and Eco.)
-
IT'S CHEMISTRY EVERYBODY. SORRY, FORGOT TO MENTION :-[
-
WTF.....?
Its Chemistry...
Srry, I'm in the commerce stream :D (Accounting, Business St. and Eco.)
I know why you were banned for 10 days. And I was wrong when I removed the ban
-
can someone please answer the question. the paper is attached.
Q2 c)
because chlorine dissolves in the sol.
-
since the gas is chlorine and it is soluble in the solution so it dissolves.
-
thanks! Another question from the same paper
Q4 (e)
-
e)
(i) you have to double the value obtained for the temperature change in ex. 2 (u'll get -8 degrees) since double the mass of the solid was used.
(ii) you have to half the value obtained in experiment 4 since double the volume of the water was used. (less concentrated lower rate of rxn) you'll get -3 degrees
(iii) since the volume of the water is more (it is double the volume) for the solid to dissolve in.
-
so adding water lowers the concentration? But i thought that according to the kinetic theory the solid will collide more with the water molecules due to the increase in water molecules. :-\
-
WTF.....?
Its Chemistry...
Srry, I'm in the commerce stream :D (Accounting, Business St. and Eco.)
I know why you were banned for 10 days. And I was wrong when I removed the ban
U mean I got banned...?
When?
-
can someone please help clear my query.
Suppose there are 2 catalysts and we have to find which one speeds up the decomposition of hydrogen peroxide, will the gas released be of the same volume in both cases?
immediate help is required.
Thanks a lot.
-
someone help pleeasssse!!!!! :'(
-
well.....the volume of the gas evolved will be the same but tym taken will differ....this is bcz the catalyst nly speeds up the reaction....it does nt affect the volume of gas being evolved.....so the reaction whch gets over faster means the catalyst used in it is efficient than the other one.......
hope this helps....
still if u hv confusion lemme kno....ill explain u mor....
-
zainy, thanks but i knew that.
zara, thanks, that's what i wanted to know but are you dead sure about the fact that the hydrogen produced is the same?
-
yes it will b the same since the amount of hydrogen peroxide used is same in both the experiments......
the wrk of the catalyst is nly to speed up the reaction without being used up....
-
thank you soo much for the timely responses! +rep
-
ur welcum ;)
-
another question bothering me -
when they say, draw a smooth line graph do they mean a straight line or a curve.
It's from question 3, page 5, qp attached
-
smooth line graph means a curve drawn free hand.....
best fit line means a st. line leaving equal points on either side n joining those points whch r the most in the same direction.....hope u get it...
-
thanks a lot! i feel much better.
-
netym dude!!!! ;)
-
I love the cooperation!!
-
Someone please help!!!
This time it's english first language. Does anyone have model answers for the english reading and writing paper, so that i can just get an idea of how to write in he exam.
Thanks
-
sorry..taking second language english.... :(
-
i have some. The document is a sample answer for nov 2008 paper 2 i think.
go thru em.
-
thank you! do you have any more?
-
that's a specimen paper along with its mark scheme. Hope they help. I'll look for more.