« previous next »
Pages: 1 ... 153 154 [155] 156 157 ... 227   Go Down

Author Topic: CHEM AND BIO HELP AND TIPS HERE  (Read 356996 times)

Offline Meticulous

  • SF Master
  • ******
  • Posts: 2486
  • Reputation: 19401
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2310 on: May 30, 2010, 05:30:41 pm »
*yawn*  ::)
Logged

Offline rhea

  • SF Immigrant
  • **
  • Posts: 66
  • Reputation: 82
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2311 on: May 30, 2010, 06:54:40 pm »
hy can some1 gime the list of soluble and insluble cmpounds..?
its differnt in diffrent books..

wht doeeeeeeeees CIE approve of?
Logged

Offline Meticulous

  • SF Master
  • ******
  • Posts: 2486
  • Reputation: 19401
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2312 on: May 30, 2010, 07:02:28 pm »
All nitrates are soluble.

All ammonium, sodium, potassium, lithium compunds are soluble.

With sulphates, all are soluble excep for barium, leade, and calcium.

With halides, all are soluble except for lead and silver

Logged

Offline the_grim_reaper

  • SF Citizen
  • ***
  • Posts: 160
  • Reputation: 180
  • Gender: Male
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2313 on: May 30, 2010, 07:11:23 pm »
Quote from: Helium on May 30, 2010, 04:25:38 pm
Whats heated and instead of melting turns into solid? ???

I suppose you're referring to sublimation. Carbon Dioxide. When solid carbon dioxide is heated (it's called dry ice By the way) it turns into a gas instead of becoming a liquid...
Logged

Offline Ivo

  • SF Geek
  • ****
  • Posts: 515
  • Reputation: 2767
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2314 on: May 30, 2010, 07:12:25 pm »
Quote from: ~ A.F ~ on May 30, 2010, 07:02:28 pm
All nitrates are soluble.

All ammonium, sodium, potassium, lithium compunds are soluble.

With sulphates, all are soluble excep for barium, leade, and calcium.

With halides, all are soluble except for lead and silver



Also most hydroxides and carbonates are insoluble except Group I hydroxides and carbonates (calcium hydroxide is slightly soluble).

Most metal oxides are insoluble except Group I and II oxides react with water.
Logged
Always willing to help!  8)
"In helping others, we shall help ourselves, for whatever good we give out completes the circle and comes back to us."

Offline CatAly$t

  • SF Citizen
  • ***
  • Posts: 241
  • Reputation: 256
  • Gender: Male
  • Ade MeLayU ke Kat $!n!???
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2315 on: May 31, 2010, 07:20:27 am »
yo ivo!

just 1 question,on the answer that u gave me,the last answer...y did u do o.5*(2+16)??

where did 2 and 16 came from?

sorry if this is a silly question because I'm very bad in chem.... :'(
Logged
InshaAllah 8 A* in IGCSE....Ameen.....

Ade MeLayU ke Kat $!n!???

Offline CatAly$t

  • SF Citizen
  • ***
  • Posts: 241
  • Reputation: 256
  • Gender: Male
  • Ade MeLayU ke Kat $!n!???
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2316 on: May 31, 2010, 07:49:11 am »
and please if somebody can do this... ???
Logged
InshaAllah 8 A* in IGCSE....Ameen.....

Ade MeLayU ke Kat $!n!???

Offline guMnam

  • !!~~**~~!!
  • SF Farseer
  • *******
  • Posts: 4242
  • Reputation: 12471
  • Gender: Male
  • !!~~guMnam~~!!
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2317 on: May 31, 2010, 08:00:35 am »
Quote from: aangel42 on May 31, 2010, 07:03:17 am
also, guys, don't know why my computer's decided to be all retarded today, but i'm not able to download the "questions paper 1 from 1994-2004" on this link: http://freeexampapers.com/Dndex.php?d=SUdDU0UvQmlvbG9neS9DSUUvMTk5MyAtIDIwMDM=
or the answers to it (first file)
it's for biology, and my computer keeps saying that it's a reported malicious site or something.
please help?????!!!!!
this is strange its workin for me......the message u get is frm ur browser of frm ur antvitus software
Logged

I <3 Challenges
Never give up :)

Offline CatAly$t

  • SF Citizen
  • ***
  • Posts: 241
  • Reputation: 256
  • Gender: Male
  • Ade MeLayU ke Kat $!n!???
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2318 on: May 31, 2010, 08:15:58 am »
Quote from: guMnam on May 31, 2010, 08:00:35 am
this is strange its workin for me......the message u get is frm ur browser of frm ur antvitus software

i think freeexampapers.com got hacked or attacked by virus....

my browser keeps telling me that this site is attacked....

but i still can download the papers....though being prompted by my browser every time i click.....
Logged
InshaAllah 8 A* in IGCSE....Ameen.....

Ade MeLayU ke Kat $!n!???

Offline guMnam

  • !!~~**~~!!
  • SF Farseer
  • *******
  • Posts: 4242
  • Reputation: 12471
  • Gender: Male
  • !!~~guMnam~~!!
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2319 on: May 31, 2010, 08:55:55 am »
Quote from: CatAly$t on May 31, 2010, 08:15:58 am
i think freeexampapers.com got hacked or attacked by virus....

my browser keeps telling me that this site is attacked....

but i still can download the papers....though being prompted by my browser every time i click.....
Logged

I <3 Challenges
Never give up :)

Offline guMnam

  • !!~~**~~!!
  • SF Farseer
  • *******
  • Posts: 4242
  • Reputation: 12471
  • Gender: Male
  • !!~~guMnam~~!!
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2320 on: May 31, 2010, 08:56:31 am »
its working for me comletely no messages no probs..
Logged

I <3 Challenges
Never give up :)

Offline Helium

  • SF Citizen
  • ***
  • Posts: 216
  • Reputation: 672
  • Knowledge is light
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2321 on: May 31, 2010, 09:02:34 am »
Quote from: CatAly$t on May 31, 2010, 08:15:58 am
i think freeexampapers.com got hacked or attacked by virus....

my browser keeps telling me that this site is attacked....

but i still can download the papers....though being prompted by my browser every time i click.....

Why would anyone try to hack freeexampapers?

it's working with me
Logged
Aiming for the top

Offline Ghost Of Highbury

  • O_o_O lala!
  • SF Farseer
  • *******
  • Posts: 4096
  • Reputation: 41428
  • Gender: Male
  • Namaskaram!
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2322 on: May 31, 2010, 10:44:12 am »
download it from www.xtremepapers.net
Logged
divine intervention!

Offline Ivo

  • SF Geek
  • ****
  • Posts: 515
  • Reputation: 2767
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2323 on: May 31, 2010, 10:59:40 am »
Quote from: aangel42 on May 31, 2010, 07:02:49 am
hey guys,

M/J 2002 Paper 1 for biology isn't posted on FEP... the mark scheme is, but the actual paper isn't.. does anyone know where I can find it?

thanksss :)

Here it is aangel42, please find the attached file.  Hope that's what you want :D
Logged
Always willing to help!  8)
"In helping others, we shall help ourselves, for whatever good we give out completes the circle and comes back to us."

Offline Ivo

  • SF Geek
  • ****
  • Posts: 515
  • Reputation: 2767
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2324 on: May 31, 2010, 11:08:18 am »
Quote from: CatAly$t on May 31, 2010, 07:20:27 am
yo ivo!

just 1 question,on the answer that u gave me,the last answer...y did u do o.5*(2+16)??

where did 2 and 16 came from?

sorry if this is a silly question because I'm very bad in chem.... :'(

Looking at that previous post, and applying the formula, you notice I used the term 'Mr'.  This just simply means the relative molecular mass - the sum of the relative atomic masses in the formula of the molecule.

The formula of water is: H2O, so looking at the periodic table: (Ar of O: 16; Ar of H: 1).  This means: H2=1+1, and O is just 16.  So in total, the Mr is: 16+2=18. 

Sorry for not explaining this in the first place.  I hope this helps :)
Logged
Always willing to help!  8)
"In helping others, we shall help ourselves, for whatever good we give out completes the circle and comes back to us."
Pages: 1 ... 153 154 [155] 156 157 ... 227   Go Up
« previous next »