« previous next »
Pages: 1 ... 5 6 [7] 8 9   Go Down

Author Topic: Chemistry Help needed!:-(  (Read 13352 times)

Offline Pharoah

  • SF Immigrant
  • **
  • Posts: 61
  • Reputation: 6
  • Gender: Male
Re: Chemistry Help needed!:-(
« Reply #90 on: May 08, 2009, 07:58:04 pm »
Thank you! My first rep gain! :D
Logged
Victory is only a stone's throw away!

Offline hyebyekadal

  • SF Citizen
  • ***
  • Posts: 182
  • Reputation: 17
Re: Chemistry Help needed!:-(
« Reply #91 on: May 08, 2009, 07:58:58 pm »
thanx man ur first one to clearly exaplin and come back and help out again Thank You again !
PS. i also plus repped you ! check it out!
Logged

unown.xu

  • Guest
Re: Chemistry Help needed!:-(
« Reply #92 on: May 08, 2009, 08:08:05 pm »
Quote from: sgvaibhav on May 08, 2009, 07:42:11 pm
if we only heat, wouldnt there be steam on the test tube that would be called condensation?

or is it the condensation that occurs after heating has been stopped?
no no no! this is how examiners can tell which centres dont do practicals with their students. have you ever tried to heat a hydrated salt? in lab? (i havent either but ive seen a vid lol)
what happens is that "water condenses on the cooler upper regions of the test tube". even while you're heating.
<half an hour later>
ive been looking for a video to show u for the past half hour, but i cant find any. really sorry. dont bother checking youtubbe or metacafe-i checked both. whatver... do it at home maybe... if u have a test tube and hydrated copper (II) sulphate crystals. lol... maybe you could make some other crystals? (most ionic compounds' crystals are hydrated)
Logged

Offline Naruto

  • SF Citizen
  • ***
  • Posts: 203
  • Reputation: 19
Re: Chemistry Help needed!:-(
« Reply #93 on: May 08, 2009, 09:12:34 pm »
@ unown.xu
hey dude can you tell me the answer to my question about those egg shells...its from the year Nov 2000 paper 6...i would be gratefull to you.
Thanks in advance
i have attached the link to that question
It is the last question, page number 12 and about the egg shells
Logged

Offline Naruto

  • SF Citizen
  • ***
  • Posts: 203
  • Reputation: 19
Re: Chemistry Help needed!:-(
« Reply #94 on: May 08, 2009, 09:35:10 pm »
hey guyz!! well i have a confusion for paper 6... i am confused about some chapter/topic that should i study them for paper 6 or not. Those topics are like (Mole, Atomic Structures, Ionic & Covalent Bond, Stiochiometry and esters)
thanx :)
Logged

Offline godfather93

  • SF Senior Citizen
  • *****
  • Posts: 720
  • Reputation: 799
  • Gender: Male
  • Tomorrow is a day that changes everyday
Re: Chemistry Help needed!:-(
« Reply #95 on: May 08, 2009, 09:58:54 pm »
paper 6 only includes the topics from the core content. so petrochemicals and polymers is not at all going tome. Basics on mole can possible come. you need to know the covalent and ionic bonding because it is the basics of chemistry.
Logged

Offline Pharoah

  • SF Immigrant
  • **
  • Posts: 61
  • Reputation: 6
  • Gender: Male
Re: Chemistry Help needed!:-(
« Reply #96 on: May 09, 2009, 06:21:32 am »
Quote
    hey dude can you tell me the answer to my question about those egg shells...its from the year Nov 2000 paper 6...i would be gratefull to you.
Thanks in advance

Ok. First you have to react it with HCl. Then filter the solution. The solution will contain CaCl2 which is soluble. If any impurities are present they will appear as residue. Now the ques is for 6 marks so you should put in practical details like use measuring cylinder to add 5 cm3 of HCl and wait till production of effervescence stops  before fitering to ensure that all CaCO3 has reacted and the moles of HCl used must be at least double that of the egg shell . And use filter paper and funnel to filter. wet the filter paper so that it becomes easier to filter. Also the filtrate can be left to evaporate and the crystals that are firmed can be observed. If only CaCl2 is present, pure crystals will be present.
Also, the reaction between CaCO3 and HCl is exothermic so you need a test tube holder and have to be careful not to burn yourself. And HCl is corrosive-care required.
« Last Edit: May 09, 2009, 06:34:12 am by Pharoah »
Logged
Victory is only a stone's throw away!

Offline Pharoah

  • SF Immigrant
  • **
  • Posts: 61
  • Reputation: 6
  • Gender: Male
Re: Chemistry Help needed!:-(
« Reply #97 on: May 09, 2009, 06:23:29 am »
Quote
  thanx man ur first one to clearly exaplin and come back and help out again Thank You again !
PS. i also plus repped you ! check it out!

Thanks dude! I do what I can. Glad to be of assistance  :)
Logged
Victory is only a stone's throw away!

Offline Naruto

  • SF Citizen
  • ***
  • Posts: 203
  • Reputation: 19
Re: Chemistry Help needed!:-(
« Reply #98 on: May 09, 2009, 10:33:16 pm »
hey...Can you guyz tell me that in chem paper6 when they ask us to draw a smooth line graph do we have to draw it with the help of ruler or without it... i mean like we make a smooth curve

@unown.xu
Thanks a lottt!!!! ;D
Logged

Offline Naruto

  • SF Citizen
  • ***
  • Posts: 203
  • Reputation: 19
Re: Chemistry Help needed!:-(
« Reply #99 on: May 09, 2009, 10:51:34 pm »
Anyone plzzz tell me i have been waiting for a long time :( im solving a past paper where im supposed to draw a smooth line graph so plzzz tell me i have to solve so many papers :(
« Last Edit: May 09, 2009, 10:59:42 pm by Naruto »
Logged

Offline Zain-Xa

  • SF Overlord
  • *********
  • Posts: 11833
  • Reputation: 10822
  • I got an "I <3 ?" written at the back of my hand
Re: Chemistry Help needed!:-(
« Reply #100 on: May 09, 2009, 10:54:29 pm »
u have to do it wid a free hand no ruler
Logged
What can I do, to make it right
Falling so hard so fast this time
What did I say, what did you do?
How did I fall in love with you?


zzzzzZZZZZZzzzzzzzzz

I'll be strong.. I'll be wrong.. all the love goes on.. Oh im just a girl tryna find a place in this worLD..  Taylor swift <3

Offline godfather93

  • SF Senior Citizen
  • *****
  • Posts: 720
  • Reputation: 799
  • Gender: Male
  • Tomorrow is a day that changes everyday
Re: Chemistry Help needed!:-(
« Reply #101 on: May 09, 2009, 10:55:03 pm »
which paper r u doing? i need to know the question to answer your question.
Logged

Offline Zain-Xa

  • SF Overlord
  • *********
  • Posts: 11833
  • Reputation: 10822
  • I got an "I <3 ?" written at the back of my hand
Re: Chemistry Help needed!:-(
« Reply #102 on: May 09, 2009, 10:56:37 pm »
Quote from: godfather93 on May 09, 2009, 10:55:03 pm
which paper r u doing? i need to know the question to answer your question.

u dont need to know the question because smooth curve alwayz means free hand no ruler
Logged
What can I do, to make it right
Falling so hard so fast this time
What did I say, what did you do?
How did I fall in love with you?


zzzzzZZZZZZzzzzzzzzz

I'll be strong.. I'll be wrong.. all the love goes on.. Oh im just a girl tryna find a place in this worLD..  Taylor swift <3

Offline godfather93

  • SF Senior Citizen
  • *****
  • Posts: 720
  • Reputation: 799
  • Gender: Male
  • Tomorrow is a day that changes everyday
Re: Chemistry Help needed!:-(
« Reply #103 on: May 09, 2009, 10:56:59 pm »
Quote from: zainy on May 09, 2009, 10:54:29 pm
u have to do it wid a free hand no ruler

depends on the question cause i just did a very similar question and it asked me to draw a smooth line graph. Turns out i had to draw a straight line with a ruler
Logged

Offline Zain-Xa

  • SF Overlord
  • *********
  • Posts: 11833
  • Reputation: 10822
  • I got an "I <3 ?" written at the back of my hand
Re: Chemistry Help needed!:-(
« Reply #104 on: May 09, 2009, 10:58:04 pm »
but i have heard frm my teacher for smooth line they give marks for widout ruler
Logged
What can I do, to make it right
Falling so hard so fast this time
What did I say, what did you do?
How did I fall in love with you?


zzzzzZZZZZZzzzzzzzzz

I'll be strong.. I'll be wrong.. all the love goes on.. Oh im just a girl tryna find a place in this worLD..  Taylor swift <3
Pages: 1 ... 5 6 [7] 8 9   Go Up
« previous next »