Chemistry Paper 3 IGCSE Oct.Nov. 2013 Discussion

[qasimnisar2121]

HAHAHAHA! I just go straight up & sit, on 12th november I was the first one! B|

(0625) oct/nov 2011 ppr 33 Q 11 b (ii)
Can you temme how to do the ^ question? :/

i am on it!!

 

[SarahCh8]

alright, I'm waiting.

 

[qasimnisar2121]

alright, I'm waiting.

ok so it will be based on the same principals of finding the half lives... but this time we have to find the whole age instead of half lives so its more easy!! we will just look at the decaying half life of carbon 14, the units of skeleton have no importance here so , so the half life of carbon 14 to decay is 5730 years.... and we know that to find the HALF LIVES we divide the total years by three... so here as we have to find the TOTAL years by half live.... we will multiply 5730 by 3 , and we will get the age of that skeleton 17,190 years! which is actually equals to 3-half lives of carbon-14 !

 

[SarahCh8]

Where did 3 come from?

 

[qasimnisar2121]

Where did 3 come from?

somewhere from heaven!! wait i guess i did it wrong..... i think i cant do it!! oh well practice only 31.... this is 33 and its the most different from 31!

 

[SarahCh8]

hahahahahahaha, still.
Buh, anyway Jazak'Allah! And, I knew that with 3 we can get the answer, buh don't know from where 3 comes.

 

[Lanocaster]

Guys, temme the answers what you guys wrote? ​

Which form the covalent molecules, in the first question? I don't remember.​

What did you you write the answer for how photochromic glass works? It's a reversible reaction.​

Why is ammonia based something is used, though it expensive? Because it requires less electricity and more yield​

About the charcoal & coke thing? Charcoal has less carbon​

Which metals don't react with acid & how can we experiment & show & which metal forms purple/pink solution & when zinc used, what will be observed? Managanate; turns colourless​

Why is there's different concentration of AgNo3 & potassium dichromate used? Because two moles of AgNO3 react with 1 mole of potassium dichromate​

What will happen when transition metal oxidation isn't written? you cannot write the correct formula​

What was the name of reaction when glucose changed to starch? condensation polymerisation​

What was the ester, unsaturated or saturated? saturated​

 

[qasimnisar2121]

hahahahahahaha, still.
Buh, anyway Jazak'Allah! And, I knew that with 3 we can get the answer, buh don't know from where 3 comes.

haha!! well actually in our variant 31 radioactivity doesnt comes... it comes in multiple choice!! so dont need to worry!

 

[SarahCh8]

InshaAllah!

 

[qasimnisar2121]

InshaAllah!

well u did ur revision or doing?? i'll start it now... or soon

 

[SarahCh8]

WOW! That's too early. :O

I'm almost done with revision.

 

[fizzyy]

i got 0.664 grams too its right i think..also 32 variant what was the answer for the agcl question..the sunglasses one.

 

[22shimmer22girly]

hey guys the paper was so long.....i was writting till the last second !!! and i also got 0.664 ...anyways what was the answer for the metal which turns pink solution something ???

 

[soooso]

hey guys the paper was so long.....i was writting till the last second !!! and i also got 0.664 ...anyways what was the answer for the metal which turns pink solution something ???

which question r u asking about?

 

[SarahCh8]

Guys, how was the physics ppr 31?

 

[22shimmer22girly]

which question r u asking about?

the question which said chose metals from the above list, i cant remeber the exact question number but you just had to choose some metals and answer some questions...btw what did u get ?? i wrote manganese because it was the only transition element and from my knowledge it forms many colored compounds as it has many oxidation numbers..

 

[soooso]

the question which said chose metals from the above list, i cant remeber the exact question number but you just had to choose some metals and answer some questions...btw what did u get ?? i wrote manganese because it was the only transition element and from my knowledge it forms many colored compounds as it has many oxidation numbers..

yesss me2 i wrote "Mn" because it's a strong oxidising agent,, so it will change to colourless

 

[Skyfall19]

Guys, temme the answers what you guys wrote? ​

Which form the covalent molecules, in the first question?​

What did you you write the answer for how photochromic glass works?​

Why is ammonia based something is used, though it expensive?​

About the charcoal & coke thing?​

Which metals don't react with acid & how can we experiment & show & which metal forms purple/pink solution & when zinc used, what will be observed?​

Why is there's different concentration of AgNo3 & potassium dichromate used?​

What will happen when transition metal oxidation isn't written?​

What was the name of reaction when glucose changed to starch?​

What was the ester, unsaturated or saturated?​

1:It was E and D Cox Covalent Molecules Are not able to conduct electricity either in aq or solid.
2:It was like a tough one u can gain the first mark by stating that it is a photochemical process the other two marks are like silver is reduced cucl is oxidised to cucl2 sumthin like dat now lets hope examiner thinks its correct
3:Electric arc process needs a lot of electricity it is expenisve.
4:I wrote it like vague one charcoal low ash content made of wood coke is from coal when burns produces co2 and other harmful gases while charcoal emits less harmful gases/
5:i diidnt see this qstn in tha papr.?
6:i didnt kknew that i wrote just like for fair exp
7:difficulty in wrting the formual of its compound difficluty in predicting its chemical properties.
8:Hydrolysis
9:it was saturated i wrote unsaturated...God Know Why?

 

[soooso]

1:It was E and D Cox Covalent Molecules Are not able to conduct electricity either in aq or solid.
2:It was like a tough one u can gain the first mark by stating that it is a photochemical process the other two marks are like silver is reduced cucl is oxidised to cucl2 sumthin like dat now lets hope examiner thinks its correct
3:Electric arc process needs a lot of electricity it is expenisve.
4:I wrote it like vague one charcoal low ash content made of wood coke is from coal when burns produces co2 and other harmful gases while charcoal emits less harmful gases/
5:i diidnt see this qstn in tha papr.?
6:i didnt kknew that i wrote just like for fair exp
7:difficulty in wrting the formual of its compound difficluty in predicting its chemical properties.
8:Hydrolysis
9:it was saturated i wrote unsaturated...God Know Why?

what?? i think that the reaction from glucose to starch is a condensation polymerisation reaction

 

[fizzyy]

polymerisation reaction should be enough!