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Author Topic: CHEM AND BIO HELP AND TIPS HERE  (Read 350942 times)

Offline Vin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2610 on: June 05, 2010, 02:29:01 pm »
Quote from: MasterMath on June 05, 2010, 02:26:34 pm
but hmm... How does it neutralize the acidity of the soil without increasing its Ph >_< ?
I got what you mean but im a bit confused

CaCO3 insoluble in water, no change in pH. Hence pH remains 7

CaO, partially soluble in water, forms Ca(OH)2- a base, so the pH can go above 7 get it?
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Offline MasterMath

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2611 on: June 05, 2010, 02:29:21 pm »
Quote from: nid404 on June 05, 2010, 02:27:45 pm
Carbonate is a salt...so it's pH is neutral
whereas oxide of group 2 metals are alkaline.
Righttt >_<.. thanks vmuch
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Offline MasterMath

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2612 on: June 05, 2010, 02:36:08 pm »
If you answer questions like using the AS syllabus
for example they ask you why Ammonia is liquid while Nitrogen is gas ..
Cant you say the intermolecular forces in ammonia are hydrogen bonds while nitrogen is VDW?
They said in MS Ammonia has a higher boiling point .. thats true also XD
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**RoRo**

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2613 on: June 05, 2010, 03:21:30 pm »
Questionnn!  ;D
Explain why metals are often used in the form of alloys?
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elemis

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2614 on: June 05, 2010, 03:25:01 pm »
The main reason is since the alloy may (but not always) be stronger.
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Offline Vin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2615 on: June 05, 2010, 03:29:27 pm »
Quote from: **RoRo** on June 05, 2010, 03:21:30 pm
Questionnn!  ;D
Explain why metals are often used in the form of alloys?

Iron to stainless steel> does not rust
Alloys are stronger/harder
Can be used in specific proportion to create 'customised' properties :: Alloy of Al(Zn+Mg+cu)-Light weight and strong
Alloy-solder-to lower melting pt.
Brass-easy to shape
Cupro-nickel-Usually cheaper than silver(used as coins)

any more would be appreciated..
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elemis

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2616 on: June 05, 2010, 03:32:44 pm »
@Vin  we don't specifically need to know all the characteristics for alloys.
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Offline Vin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2617 on: June 05, 2010, 03:36:39 pm »
Quote from: Ari Ben Canaan on June 05, 2010, 03:32:44 pm
@Vin  we don't specifically need to know all the characteristics for alloys.


Yes, absolutely. But our teacher made us learn us all so I know most of them. ;D
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Offline wstrawberries

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2618 on: June 05, 2010, 03:37:19 pm »
How do you show the charges in a diagram showing electronic configuration? I am kind of confused about how to show it  ???
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Offline Vin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2619 on: June 05, 2010, 03:38:50 pm »


^^second diagram
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elemis

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2620 on: June 05, 2010, 03:40:05 pm »
Quote from: wstrawberries on June 05, 2010, 03:37:19 pm
How do you show the charges in a diagram showing electronic configuration? I am kind of confused about how to show it  ???

LOOK
« Last Edit: June 05, 2010, 03:49:11 pm by Ari Ben Canaan »
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Offline Raywin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2621 on: June 05, 2010, 03:40:19 pm »
Hey guys. :) a small doubt, if asked to draw an ionic bonding diagram between any non-metal and metal wht exactly do we draw?  ???  ???  ??? OH i was just solved... by ari.. :P
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;D

Offline Meticulous

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2622 on: June 05, 2010, 03:41:26 pm »
Thanks vin. +rep.
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Offline wstrawberries

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2623 on: June 05, 2010, 03:41:49 pm »
Thanks Vin and Ari :D
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elemis

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2624 on: June 05, 2010, 03:41:59 pm »
@Raywin

Look above your post.
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