« previous next »
Pages: 1 ... 136 137 [138] 139 140 ... 227   Go Down

Author Topic: CHEM AND BIO HELP AND TIPS HERE  (Read 333050 times)

Offline The Golden Girl =D

  • Without Allah I'm nothing <3
  • Honorary Member
  • SF Overlord
  • *****
  • Posts: 13757
  • Reputation: 65532
  • Ain't Nothin worth your tears =D
    • www.thegoldengirl157.blogspot.com
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2055 on: May 24, 2010, 08:04:22 pm »
Quote from: Ivo on May 24, 2010, 08:02:43 pm
Has been answered previously

where , give me the link ,or number of page plz ???
Logged
Verily, in the remembrance of Allah do hearts find rest(13:28)

Please, Don't forget to Include GG in your Prayers =D

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 #2056 on: May 24, 2010, 08:04:54 pm »
Both the options can be used, however, having molten CuSO4 uses more energy and thus its wiser to use aqueous copper sulfate.
Logged
divine intervention!

Offline Helium

  • SF Citizen
  • ***
  • Posts: 216
  • Reputation: 672
  • Knowledge is light
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2057 on: May 24, 2010, 08:06:12 pm »
Q)

What is a Basic oxide?
Logged
Aiming for the top

Offline Vin

  • SF V.I.P
  • ********
  • Posts: 7914
  • Reputation: 52609
  • Gender: Male
    • Theory of Life - A new skew.
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2058 on: May 24, 2010, 08:07:20 pm »
Quote from: the golden girl on May 24, 2010, 07:47:54 pm
plz explain Q20 year november 2007  

thx in advance

answer is B .. because carbon will react with oxygen from air to form CO2 and escape .. so mass of carbon dec.

copper reacts with O2 to form oxide which 'gains' mass due to oxygen
Logged

Offline Ivo

  • SF Geek
  • ****
  • Posts: 515
  • Reputation: 2767
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2059 on: May 24, 2010, 08:07:28 pm »
Quote from: the golden girl on May 24, 2010, 08:04:22 pm
where , give me the link ,or number of page plz ???

carbon reacts with air to form carbon dioxide, released, so mass of carbon decreases.

copper reacts wtih oxygen to form copper oxide, which is soluble, so gets accumulated.

so answer is b
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 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 #2060 on: May 24, 2010, 08:07:38 pm »
Quote from: Ivo on May 24, 2010, 08:00:54 pm
So all compunds have oxidation number of 0?

Then why is it that sulphur is +4, i thought cos it's in group 6, then it is -2.

how do oxidation numbers work?

its not possible to explain everything now...its a long long concept..

check the website i had posted earlier and read the rules..that shud help u

@helium = a metal oxide that is base, which forms a hydroxide when ombined with water.
i didnt say all compounds have oxidation number of 0, the OVERALL! oxidation number is 0...like SO2, if O2's is -4, then S's shud be +4 to make the overall oxidation number 0.
Logged
divine intervention!

Offline The Golden Girl =D

  • Without Allah I'm nothing <3
  • Honorary Member
  • SF Overlord
  • *****
  • Posts: 13757
  • Reputation: 65532
  • Ain't Nothin worth your tears =D
    • www.thegoldengirl157.blogspot.com
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2061 on: May 24, 2010, 08:07:56 pm »
Quote from: Helium on May 24, 2010, 08:06:12 pm
Q)

What is a Basic oxide?

metal oxide


Logged
Verily, in the remembrance of Allah do hearts find rest(13:28)

Please, Don't forget to Include GG in your Prayers =D

Offline Ivo

  • SF Geek
  • ****
  • Posts: 515
  • Reputation: 2767
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2062 on: May 24, 2010, 08:08:44 pm »
Quote from: A@di on May 24, 2010, 08:07:38 pm
its not possible to explain everything now...its a long long concept..

check the website i had posted earlier and read the rules..that shud help u

@helium = a metal oxide that is base, which forms a hydroxide when ombined with water.
i didnt say all compounds have oxidation number of 0, the OVERALL! oxidation number is 0...like SO2, if O2's is -4, then S's shud be +4 to make the overall oxidation number 0.


sory which website?
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 The Golden Girl =D

  • Without Allah I'm nothing <3
  • Honorary Member
  • SF Overlord
  • *****
  • Posts: 13757
  • Reputation: 65532
  • Ain't Nothin worth your tears =D
    • www.thegoldengirl157.blogspot.com
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2063 on: May 24, 2010, 08:08:58 pm »
Quote from: Ivo on May 24, 2010, 08:07:28 pm
carbon reacts with air to form carbon dioxide, released, so mass of carbon decreases.

copper reacts wtih oxygen to form copper oxide, which is soluble, so gets accumulated.

so answer is b

what abt Q35  :-[ :-[
Logged
Verily, in the remembrance of Allah do hearts find rest(13:28)

Please, Don't forget to Include GG in your Prayers =D

Offline Vin

  • SF V.I.P
  • ********
  • Posts: 7914
  • Reputation: 52609
  • Gender: Male
    • Theory of Life - A new skew.
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2064 on: May 24, 2010, 08:09:14 pm »
Quote from: Helium on May 24, 2010, 08:06:12 pm
Q)

What is a Basic oxide?

*ahem* google ..  :P

reacts with acid to give salt and water
reacts with water to give a base
Logged

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 #2065 on: May 24, 2010, 08:10:11 pm »
Quote from: Ivo on May 24, 2010, 08:07:28 pm
carbon reacts with air to form carbon dioxide, released, so mass of carbon decreases.

copper reacts wtih oxygen to form copper oxide, which is soluble, so gets accumulated.

so answer is b

35) A , K + Na = 1 + 6.5 = 7.5
Logged
divine intervention!

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 #2066 on: May 24, 2010, 08:10:57 pm »
Logged
divine intervention!

Offline Helium

  • SF Citizen
  • ***
  • Posts: 216
  • Reputation: 672
  • Knowledge is light
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2067 on: May 24, 2010, 08:11:53 pm »
Quote from: ~VIN1094~ on May 24, 2010, 08:09:14 pm
*ahem* google ..  :P

reacts with acid to give salt and water
reacts with water to give a base
Thanks thats what i wanted
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 #2068 on: May 24, 2010, 08:12:26 pm »
Quote from: the golden girl on May 24, 2010, 07:53:18 pm
??? ??? ??? :-\ :-\ :-\ :-[

i'm waitin   ::) ::)

38) B - it burns in air, it dissolves.. it cannot be polymerized.
Logged
divine intervention!

Offline Vin

  • SF V.I.P
  • ********
  • Posts: 7914
  • Reputation: 52609
  • Gender: Male
    • Theory of Life - A new skew.
Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2069 on: May 24, 2010, 08:12:41 pm »
Quote from: the golden girl on May 24, 2010, 08:08:58 pm
what abt Q35  :-[ :-[

ok the only elements "singly" charged are Na and K add 6.5 and 1 = 7.5 ie A
Logged
Pages: 1 ... 136 137 [138] 139 140 ... 227   Go Up
« previous next »