All chemistry Doubts here :)

[anonymous123]

Guys how is sponge a solid ?? See...A solid has a definite shape, incompressible, high density and a sponge denies these properties.It most likely fits into the category of liquids like it can be stuffed into a small container and it will take its shape.It has a lower density compared to solids and it can be compressed. :x

 

[Ramosk95]

No, transition metals will not always have the valency of 2
Is it like if we add water to NaOH the ph will remain the same (original ph of NaOH) and if we add NaOH to water the PH will increase?

ph of water is 7 (neutral) so the acidity decreases bcz naoh is a strong base lests say 13ph

 

[zkapoor]

http://www.xtremepapers.me/CIE/International A And AS Level/9701 - Chemistry/9701_w10_qp_12.pdf

Qestion 18.

It definitely isn't A or D.
Bromine and therefore the vapour is brown and since it's a covalent compound it'll be soluble in covalent/organic (basically non polar) solvents. The other two, I really have no clue. You're posting an A level question in an IGCSE forum bro

 

[AStarHunter]

guyz, i have a doubt here Q4(A)(ii)---> http://www.xtremepapers.me/CIE/inde...GCSE/0620 - Chemistry/&file=0620_w06_qp_3.pdf
Mark scheme says NOT incomplete combustion (http://www.xtremepapers.me/CIE/inde...GCSE/0620 - Chemistry/&file=0620_w06_ms_3.pdf)
But the examiner`s report says All that was required was a realisation that toxic carbon monoxide would form (as a result of incomplete combustion due to inadequate oxygen supply). Here`s the link : http://www.xtremepapers.me/CIE/index.php?dir=Cambridge IGCSE/0620 - Chemistry/&file=0620_w06_er.pdf
I am not really sure what I`m supposed to do cause I just wrote what the examiner`s report said !!
Weird CIE :%) :crazy:

 

[xIshtar]

guyz, i have a doubt here Q4(A)(ii)---> http://www.xtremepapers.me/CIE/inde...GCSE/0620 - Chemistry/&file=0620_w06_qp_3.pdf
Mark scheme says NOT incomplete combustion (http://www.xtremepapers.me/CIE/inde...GCSE/0620 - Chemistry/&file=0620_w06_ms_3.pdf)
But the examiner`s report says All that was required was a realisation that toxic carbon monoxide would form (as a result of incomplete combustion due to inadequate oxygen supply). Here`s the link : http://www.xtremepapers.me/CIE/index.php?dir=Cambridge IGCSE/0620 - Chemistry/&file=0620_w06_er.pdf
I am not really sure what I`m supposed to do cause I just wrote what the examiner`s report said !!
Weird CIE :%) :crazy:

It's saying that you don't reason by saying incomplete combustion. You should say that it is dangerous as carbon monoxide would form as a result of incomplete combustion, which is poisonous and damaging to our health.

Basically, they are just saying you don't get a mark from incomplete combustion, but it is correct, you have to say carbon monoxide...

If you get what I'm saying.

 

[AStarHunter]

thanx xIshtar ,, I really get it now

 

[xIshtar]

thanx xIshtar ,, I really get it now

Any time dude..

Keep the questions rolling, bored of doing paper 3's myself D:

 

[JmCullen]

hey! im bored over here too =__="
but i know i have to catch up the studies.. urghx!! >_<
tiredddd~~~

ok.. im just being random here.. cuz im too bored..

 

[xIshtar]

hey! im bored over here too =__="
but i know i have to catch up the studies.. urghx!! >_<
tiredddd~~~

ok.. im just being random here.. cuz im too bored..

xD..

I've kinda done most of the past papers on the site for my remaining exams.. Gonna go start 1990s ones now

 

[JmCullen]

hey! im bored over here too =__="
but i know i have to catch up the studies.. urghx!! >_<
tiredddd~~~

ok.. im just being random here.. cuz im too bored..

xD..

I've kinda done most of the past papers on the site for my remaining exams.. Gonna go start 1990s ones now

woaw! 1990s.. AWESOME! :good:
I haven't finish all of the past papers..
that's why gonna catch up! haha.. :lol:
but it's kinda bored keep reading past papers..
gonna faint soon.. :%) (exaggerating) hahahaha.. :Yahoo!:

 

[xIshtar]

hey! im bored over here too =__="
but i know i have to catch up the studies.. urghx!! >_<
tiredddd~~~

ok.. im just being random here.. cuz im too bored..

xD..

I've kinda done most of the past papers on the site for my remaining exams.. Gonna go start 1990s ones now

woaw! 1990s.. AWESOME! :good:
I haven't finish all of the past papers..
that's why gonna catch up! haha.. :lol:
but it's kinda bored keep reading past papers..
gonna faint soon.. :%) (exaggerating) hahahaha.. :Yahoo!:

Heh, Chemistry is what it is.. I'm lucky, 4 exams left then 3 months of holiday, and 3/4 papers are multiple choice

 

[JmCullen]

Heh, Chemistry is what it is.. I'm lucky, 4 exams left then 3 months of holiday, and 3/4 papers are multiple choice

haha.. i'm much better. i left 2 papers..
both are chemistry..
paper 1 and paper 3..
that's why i said im gonna faint soon. hahaha..
when is your last paper?

 

[anonymous123]

Guys how is sponge a solid ?? See...A solid has a definite shape, incompressible, high density and a sponge denies these properties.It most likely fits into the category of liquids like it can be stuffed into a small container and it will take its shape.It has a lower density compared to solids and it can be compressed. :x

Plz??

 

[xIshtar]

Heh, Chemistry is what it is.. I'm lucky, 4 exams left then 3 months of holiday, and 3/4 papers are multiple choice

haha.. i'm much better. i left 2 papers..
both are chemistry..
paper 1 and paper 3..
that's why i said im gonna faint soon. hahaha..
when is your last paper?

Friday June 10th ):

Guys how is sponge a solid ?? See...A solid has a definite shape, incompressible, high density and a sponge denies these properties.It most likely fits into the category of liquids like it can be stuffed into a small container and it will take its shape.It has a lower density compared to solids and it can be compressed. :x

Plz??

A sponge can't be poured, and it doesn't really adapt to the shape of it's containers, as it just gets compressed, meaning that it does not fully take the shape.

So a sponge is most definitely not classified as a liquid.

 

[JmCullen]

Heh, Chemistry is what it is.. I'm lucky, 4 exams left then 3 months of holiday, and 3/4 papers are multiple choice

haha.. i'm much better. i left 2 papers..
both are chemistry..
paper 1 and paper 3..
that's why i said im gonna faint soon. hahaha..
when is your last paper?

Friday June 10th ):

:shock:
GOOD LUCK!!!!
my exam end on 9th.

 

[AStarHunter]

My exam also ends on the 10 th ! JmCullen, u`re so lucky--- on the 9th
btw guyz, do u get the rates of reaction topic ? i don`t and Q7 in this paper (http://www.xtremepapers.me/CIE/inde...GCSE/0620 - Chemistry/&file=0620_w06_qp_3.pdfand mark scheme : http://www.xtremepapers.me/CIE/inde...GCSE/0620 - Chemistry/&file=0620_w06_ms_3.pdf) is confusing me !!
if ethanoic acid is a weaker acid shouldn`t that mean that there are less particles and therefore, less reaction and less hydrogen produced ?!
I feel really stupid

 

[zkapoor]

What, you mean why there's a same final volume? You have to assume (actually it might even be stated) that the ethanoic acid used is in excess. So the final volume of Hydrogen produced will be the same. However, since it's a weaker acid the SPEED of the reaction will be less so the slope of the graph will be less

 

[zkapoor]

The key, I would say, is that the eth is 1 mol/dm^3 as well, so the same number of H+ ions are present in the solution. It's just harder for the ones in eth to dissociate from the compound SO the reaction is slower SO lower slope

 

[zkapoor]

@XIshtar -
DAMN, that is lucky. So you take bio, eco, chem and some variation of lit which doesn't require paper 5 i assume? Lucky. Lit P5 is a NIGHTMARE. And I have additional mathematics to do as well

 

[HyDraZin3]

Question:- http://www.xtremepapers.me/CIE/Cambridg ... _qp_33.pdf
5 (b) (iv)

Mark scheme:- http://www.xtremepapers.me/CIE/Cambridg ... _ms_33.pdf

I am not able to understand the meaning of the word "dibasic" and from where the double bond came