Chemistey Doubts

[JmCullen]

how do you know it's propene?
there is 4 Carbon and also 2 oxygen..

 

[haochen]

ohh srry i thought u asked for 3) d) i)
my bad
wait a min and ill try to post the answer

 

[JmCullen]

ohh srry i thought u asked for 3) d) i)
my bad
wait a min and ill try to post the answer

haha.. okok! take ur time

 

[haochen]

the answer is......
in the attachment but i know ull ask hw so :
if they ask u to draw a polymer , all u need to do is break the double bond between C and C.
and put them in parenthesis with a line (like the one i draw) and a small "n" (so it continue until n time)
draw everything the same just break the double bond and make it one

hope that helped

 

[JmCullen]

the answer is......
in the attachment but i know ull ask hw so :
if they ask u to draw a polymer , all u need to do is break the double bond between C and C.
and put them in parenthesis with a line (like the one i draw) and a small "n" (so it continue until n time)
draw everything the same just break the double bond and make it one

hope that helped

ohhh!
ok!
cause i thought there will be water as the by-product or something .. pheww~

ok. same paper.
question 5(e)

thanks thanks thanks a lot!

 

[xIshtar]

The ionic structure contains ions arranged in a regular pattern, So, positive, negative, positive negative, positive, negative. No two positives should be directly below/above or to the side..

By positive I mean caesium and by negative, chlorine..


So:
Cs, Cl, Cs, Cl, Cs, Cl
Cl, Cs, Cl, Cs, Cl, Cs
Cs, Cl, Cs, Cl, Cs, Cl.

Something like that.

 

[JmCullen]

The ionic structure contains ions arranged in a regular pattern, So, positive, negative, positive negative, positive, negative. No two positives should be directly below/above or to the side..

By positive I mean caesium and by negative, chlorine..


So:
Cs, Cl, Cs, Cl, Cs, Cl
Cl, Cs, Cl, Cs, Cl, Cs
Cs, Cl, Cs, Cl, Cs, Cl.

Something like that.

so, have to draw it like a box?

 

[xIshtar]

No, draw the ions with circles, distinguishing between them by placing their symbol inside.

 

[JmCullen]

No, draw the ions with circles, distinguishing between them by placing their symbol inside.

errr.. do u mind to draw it?
im kinda confuse. :%)

 

[saraiqbal123]

Re: chemistry

i have some problem in the following question i will really appriciate if u ppl help me in this!!
http://www.xtremepapers.me/CIE/Cambridg ... _qp_32.pdf
question number 8(c) in this link.


this is the mark scheme:
http://www.xtremepapers.me/CIE/Cambridg ... _ms_32.pdf

can anyone do this? i'm stuck too!
im stuck in the mole of lead(II) nitrate..
why it's 0.0133 ??? :%)

 

[saraiqbal123]

could u plz answer my question em really stuck!!

 

[JmCullen]

Re: chemistry

i have some problem in the following question i will really appriciate if u ppl help me in this!!
http://www.xtremepapers.me/CIE/Cambridg ... _qp_32.pdf
question number 8(c) in this link.


this is the mark scheme:
http://www.xtremepapers.me/CIE/Cambridg ... _ms_32.pdf

can anyone do this? i'm stuck too!
im stuck in the mole of lead(II) nitrate..
why it's 0.0133 ??? :%)

i've did it in the previous post.
try to find it.

 

[HorsePower]

No, draw the ions with circles, distinguishing between them by placing their symbol inside.

errr.. do u mind to draw it?
im kinda confuse. :%)

it'll be something like this i guess

 

[gary221]

cud sum1 pls help me with this????

P.S. with an explnation!!! :friends: :friends: :friends:

It's A..
unsaturated should be double bond..
Then, C is acid.
acid can't be neutral in water.
so it's A..

jeez i was so stupid!!!!
thnx bro!!!

 

[xIshtar]

No, draw the ions with circles, distinguishing between them by placing their symbol inside.

errr.. do u mind to draw it?
im kinda confuse. :%)

it'll be something like this i guess

Exactly like that. Sorry, I wasn't checking the thread myself..

Big thanks to Horsepower for going out of his way, so I didn't have to

 

[JmCullen]

cud sum1 pls help me with this????

P.S. with an explnation!!! :friends: :friends: :friends:

It's A..
unsaturated should be double bond..
Then, C is acid.
acid can't be neutral in water.
so it's A..

jeez i was so stupid!!!!
thnx bro!!!

welcome

 

[JmCullen]

No, draw the ions with circles, distinguishing between them by placing their symbol inside.

errr.. do u mind to draw it?
im kinda confuse. :%)

it'll be something like this i guess

Thanks a lot!!!

 

[JmCullen]

http://www.xtremepapers.me/CIE/index.ph ... _qp_03.pdf

4(b)(ii)

----------------------------------------------------

how did you know which compound decomposes or not?

http://www.xtremepapers.me/CIE/index.ph ... 8_ms_3.pdf

6(b)(ii)

 

[xIshtar]

http://www.xtremepapers.me/CIE/index.php?dir=Cambridge%20IGCSE/0620%20-%20Chemistry/&file=0620_w08_qp_03.pdf

4(b)(ii)

----------------------------------------------------

how did you know which compound decomposes or not?

http://www.xtremepapers.me/CIE/index.ph ... 8_ms_3.pdf

6(b)(ii)

For 4(b)(ii):

92.3/12 = 7.7
7.7/1 = 7.7

Taking ratios.. 7.7:7.7
=> 1:1.


For 6(b)(ii):

Alkali metals apart from Lithium do not decompose, so the first is no reaction, and the second is calcium oxide + water.

 

[JmCullen]

http://www.xtremepapers.me/CIE/index.php?dir=Cambridge%20IGCSE/0620%20-%20Chemistry/&file=0620_w08_qp_03.pdf

4(b)(ii)

----------------------------------------------------

how did you know which compound decomposes or not?

http://www.xtremepapers.me/CIE/index.ph ... 8_ms_3.pdf

6(b)(ii)

For 4(b)(ii):

92.3/12 = 7.7
7.7/1 = 7.7

Taking ratios.. 7.7:7.7
=> 1:1.


For 6(b)(ii):

Alkali metals apart from Lithium do not decompose, so the first is no reaction, and the second is calcium oxide + water.

hmm..
where is the 12 from?
is it the mass of 1 carbon atom???