« previous next »
Pages: 1 ... 20 21 [22] 23 24 ... 56   Go Down

Author Topic: Chemistry Help HERE ONLY !!  (Read 106219 times)

Offline lana

  • SF Immigrant
  • **
  • Posts: 112
  • Reputation: 916
  • Gender: Female
Re: Chemistry Help HERE ONLY !!
« Reply #315 on: May 29, 2009, 04:01:38 pm »
no I'm right exothermic is when energy is given out so the temperature increases and endothermic is when energy is taken so the temperature decreases but i just misunderstood the question that's all ....!!!
Logged
''To be yourself in a world that is constantly trying to make you something else is the greatest accomplishment.''

Offline unknown 101

  • SF Joker
  • SF Master
  • ******
  • Posts: 1660
  • Reputation: 5946
  • Gender: Male
  • FEELING GREATER THAN EVERR :D
Re: Chemistry Help HERE ONLY !!
« Reply #316 on: May 29, 2009, 04:05:54 pm »
Quote from: lana on May 29, 2009, 04:01:38 pm
no I'm right exothermic is when energy is given out so the temperature increases and endothermic is when energy is taken so the temperature decreases but i just misunderstood the question that's all ....!!!

actually the first time u asked was wrong , lol, but now u know the right concept, so stop makin a big fuss about it , haha,lol  :P
Logged

Offline idol2009

  • Newbie
  • *
  • Posts: 14
  • Reputation: 0
  • Gender: Female
Re: Chemistry Help HERE ONLY !!
« Reply #317 on: May 29, 2009, 04:08:09 pm »
Hey I got a question: how are organic/carboxylic acids made? Is it by acidifying, or is it by oxidizing with potassium magnanate(or another oxidizing agent, or both together? Just confused as to if both the methods are correct, and if they are supposed to be used together...
Logged
=)

Offline unknown 101

  • SF Joker
  • SF Master
  • ******
  • Posts: 1660
  • Reputation: 5946
  • Gender: Male
  • FEELING GREATER THAN EVERR :D
Re: Chemistry Help HERE ONLY !!
« Reply #318 on: May 29, 2009, 04:10:05 pm »
Quote from: idol2009 on May 29, 2009, 04:08:09 pm
Hey I got a question: how are organic/carboxylic acids made? Is it by acidifying, or is it by oxidizing with potassium magnanate(or another oxidizing agent, or both together? Just confused as to if both the methods are correct, and if they are supposed to be used together...

carboxlyic acids are usually made by oxidising alcahols ( it doesnt matter which oxidising agent u use)
Logged

Offline unknown 101

  • SF Joker
  • SF Master
  • ******
  • Posts: 1660
  • Reputation: 5946
  • Gender: Male
  • FEELING GREATER THAN EVERR :D
Re: Chemistry Help HERE ONLY !!
« Reply #319 on: May 29, 2009, 04:11:36 pm »
thats why u sometimes get a question in fermintation about why oxygen should not be present in the flask or container
and the ans is because it can oxidise the ethanol into ethanoic acid (vinegar)
Logged

Offline unknown 101

  • SF Joker
  • SF Master
  • ******
  • Posts: 1660
  • Reputation: 5946
  • Gender: Male
  • FEELING GREATER THAN EVERR :D
Re: Chemistry Help HERE ONLY !!
« Reply #320 on: May 29, 2009, 04:21:30 pm »
i wish the 2009 chem paper 3 comes as easy as the jun 08
Logged

Offline emi

  • SF Geek
  • ****
  • Posts: 530
  • Reputation: 2581
  • former member
Re: Chemistry Help HERE ONLY !!
« Reply #321 on: May 29, 2009, 04:24:06 pm »
yes lilwayne though i have feelings that it will be
Logged
former member

Offline unknown 101

  • SF Joker
  • SF Master
  • ******
  • Posts: 1660
  • Reputation: 5946
  • Gender: Male
  • FEELING GREATER THAN EVERR :D
Re: Chemistry Help HERE ONLY !!
« Reply #322 on: May 29, 2009, 04:33:45 pm »
Quote from: emi on May 29, 2009, 04:24:06 pm
yes lilwayne though i have feelings that it will be

anywayz if u study properley , everthng is gonna be easy!!!
Logged

Offline annie_angel

  • i m not an artist; just a painter...[ths is so random]
  • SF Geek
  • ****
  • Posts: 475
  • Reputation: 352
  • Gender: Female
  • --->>>Time is nothing but a Precious Enemy<<<---
Re: Chemistry Help HERE ONLY !!
« Reply #323 on: May 29, 2009, 04:49:32 pm »
Quote from: ADi...M on May 28, 2009, 02:31:12 pm
yes..correct...forgot lithium
anyway we can change it a bit

peter's sister lauren can murder a ..............

lol
haha
HAHAHAHA!!!!!!!LOL!!!tht is so funny!!!
Logged
Dont tell God how BIG your storm is...;tell your storm how BIG your GOD is.^_^

Offline Shogun

  • SF Geek
  • ****
  • Posts: 495
  • Reputation: 25
  • Gender: Male
  • the heavens cry within the arrival of the best
Re: Chemistry Help HERE ONLY !!
« Reply #324 on: May 29, 2009, 05:19:57 pm »
lol lil wayne, wat u wanna be when u grow up?
Logged
one who masters both the pen and paper is indeed a true warrior.

\m/metal head\m/

Offline unknown 101

  • SF Joker
  • SF Master
  • ******
  • Posts: 1660
  • Reputation: 5946
  • Gender: Male
  • FEELING GREATER THAN EVERR :D
Re: Chemistry Help HERE ONLY !!
« Reply #325 on: May 29, 2009, 05:24:52 pm »
Quote from: Shogun on May 29, 2009, 05:19:57 pm
lol lil wayne, wat u wanna be when u grow up?

a doctor or pharmacist... u?
Logged

Offline Summer :]

  • SF Immigrant
  • **
  • Posts: 68
  • Reputation: 322
Re: Chemistry Help HERE ONLY !!
« Reply #326 on: May 29, 2009, 05:30:03 pm »
Quote from: ZeroZero82 on May 28, 2009, 10:48:27 am
how do we know if a reaction is endothermic?!

If heat was taken in, it's usually shown by a rise in temperature :)))
For example, you could put a thermometer inside and measure the inital temperature then the final temperature, you'll see that the temperature increased

Endothermic is the opposite way around, its shown as a decrease in temperature
Logged

Offline AN10

  • SF Immigrant
  • **
  • Posts: 51
  • Reputation: 47
  • Gender: Female
Re: Chemistry Help HERE ONLY !!
« Reply #327 on: May 29, 2009, 05:33:58 pm »
During electrolysis, what is the effect of adding water to dilute sulfuric acid on the brightness of bulb ???
Logged
“Faith is taking the first step even when you don't see the whole staircase.”

Offline unknown 101

  • SF Joker
  • SF Master
  • ******
  • Posts: 1660
  • Reputation: 5946
  • Gender: Male
  • FEELING GREATER THAN EVERR :D
Re: Chemistry Help HERE ONLY !!
« Reply #328 on: May 29, 2009, 05:35:30 pm »
Quote from: AN10 on May 29, 2009, 05:33:58 pm
During electrolysis, what is the effect of adding water to dilute sulfuric acid on the brightness of bulb ???

it makes the sulphuric acid more dilute, so the bulb's brightness decreases. i think
Logged

Offline X Abdulrahman X

  • SF Farseer
  • *******
  • Posts: 4981
  • Reputation: 3826
  • Gender: Male
Re: Chemistry Help HERE ONLY !!
« Reply #329 on: May 29, 2009, 05:39:03 pm »
Quote from: ZeroZero82 on May 28, 2009, 10:48:27 am
how do we know if a reaction is endothermic?!

The temp would fall, this is because it takes more energy/heat to break the bonds between the atoms, if it was exothermic, then more energy would be used to form new bonds, and the temp. raises
Logged
When they talk about me they say I be trippin
What they say about me doesn't make me mad 
I think they hatin cause they see me when I'm rollin
Man I can't help it that they really doin bad  =P

Big cars, Big wheels, Big chains, Big pimpin', Big money, Big Dreams ;-)
Pages: 1 ... 20 21 [22] 23 24 ... 56   Go Up
« previous next »