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Author Topic: CHEM AND BIO HELP AND TIPS HERE  (Read 357009 times)

Offline luv3life

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2265 on: May 25, 2010, 09:45:56 am »
Done with Chem P1. :) Easy.
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:) LiVe LiFe As If EaCh DaY mAy Be YoUr LaSt :)

Offline princess12

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2266 on: May 25, 2010, 09:46:56 am »
Anybody has the reactivity series list? If so, post them and thanks.
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Offline Baladya

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2267 on: May 25, 2010, 09:49:29 am »
Quote from: princess12 on May 25, 2010, 09:46:56 am
Anybody has the reactivity series list? If so, post them and thanks.


Potassium (Please)
Sodium (Send)
Calcium (Cows)
Magnesium (Monkeys)
Aluminium (And)
Carbon
Zinc (Zebras)
Iron (In)
Lead (Large)
Hydrogen
Cuppor (Cages)

 ;D ;D ;D ;D ;D
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Offline Ghost Of Highbury

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2268 on: May 25, 2010, 09:52:18 am »
Quote from: Lariemeeva on May 25, 2010, 09:40:10 am
Anyways, I know I've been a heavy load but another question,

Oct/Nov 2008 Q20 and Q21 (why is it Sulfuric acid and not HCL?)

Thanks again, and sorry for the constant trouble...

20) Barium chloride and Nitric acid. pH decreases, ppt. doesnt form as Barium chloride is soluble.

21) Sulfuric acid, Barium sulfate formed , white ppt. HCl wud produce barium chloride which is soluble.
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Offline takamorinki

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2269 on: May 25, 2010, 10:00:02 am »
Quote from: princess12 on May 25, 2010, 09:36:41 am
ok
where do u live?
takamorinki
in the middle east
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Offline Shazizzzle

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2270 on: May 25, 2010, 10:02:04 am »
Quote from: Baladya on May 25, 2010, 09:49:29 am
Potassium (Please)
Sodium (Send)
Calcium (Cows)
Magnesium (Monkeys)
Aluminium (And)
Carbon
Zinc (Zebras)
Iron (In)
Lead (Large)
Hydrogen
Cuppor (Cages)

 ;D ;D ;D ;D ;D


LOL at your signature! XD
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Offline Baladya

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2271 on: May 25, 2010, 10:04:04 am »
heheeheheh xD ;D I WISH my parents used it  :D
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Offline Shazizzzle

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2272 on: May 25, 2010, 10:08:26 am »
Quote from: Baladya on May 25, 2010, 10:04:04 am
heheeheheh xD ;D I WISH my parents used it  :D

ROFLOL! :D
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Offline Lariemeeva

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2273 on: May 25, 2010, 10:43:11 am »
Quote from: A@di on May 25, 2010, 09:52:18 am
20) Barium chloride and Nitric acid. pH decreases, ppt. doesnt form as Barium chloride is soluble.

21) Sulfuric acid, Barium sulfate formed , white ppt. HCl wud produce barium chloride which is soluble.

So the PH decreases because chloride is an alkline therefore it neutralises it?
Plus is it always that when an acid reacts with an oxide it forms a salt?
« Last Edit: May 25, 2010, 10:46:29 am by Lariemeeva »
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Offline Ghost Of Highbury

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2274 on: May 25, 2010, 10:46:30 am »
Quote from: Lariemeeva on May 25, 2010, 10:43:11 am
So the PH decreases because chloride is an alkline therefore it neutralises it?



pH decreases because nitric acid is formed.. ph<7 = acidic..

Barium nitrate + HCl = Barium nitrate + Nitric acid.

« Last Edit: May 25, 2010, 10:58:21 am by A@di »
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Offline ambitious94

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2275 on: May 25, 2010, 10:47:48 am »
Quote from: Baladya on May 25, 2010, 10:04:04 am
heheeheheh xD ;D I WISH my parents used it  :D
LOLLLLLLLLLLLLLLLLLLLLLLLLLL...can't stop laughin!!! I wish my examiner's parents had used it ;)
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Offline Lariemeeva

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2276 on: May 25, 2010, 10:55:20 am »
^^Barium chloride + HCl= Barium nitrate + Nitric acid.?
Typo?

But is Chlorine and Chlorides overall acidic or basic?
and is it always that when an acid reacts with an oxide it forms a salt?
« Last Edit: May 25, 2010, 11:01:17 am by Lariemeeva »
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Offline Ghost Of Highbury

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2277 on: May 25, 2010, 11:00:13 am »
Quote from: Lariemeeva on May 25, 2010, 10:55:20 am
^^Barium chloride + HCl= Barium nitrate + Nitric acid.?
Typo?

But is Chlorine and Chlorides overall acidic or basic?
and is it always that when an acid reacts with an oxide it forms a salt?

sorry, typo.

acidic or basic depends on OH- and H+ ions being present not chlorides/chlorine.

no not always..reactivity series
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Offline rimrim

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2278 on: May 25, 2010, 11:01:52 am »
anyone tell me what the test of water related to cobalt chloride..
when is it pink and when is it beomes blue ?? ???
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Offline Lariemeeva

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2279 on: May 25, 2010, 11:12:02 am »
A new isotope of a divalent metal is discovered. Some students are asked to predict its
properties.
Which student’s predictions are correct?


number of electrons  -  bonding in the oxide
in outer shell
                                     
A      2                                covalent
B      2                                  ionic
C      6                                covalent
D      6                                  ionic

Why is it B and not D?
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