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Chemistry doubt

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acash09:
Hey friends, what happens when an impurity is present in a substance, does:


* boiling point change; increase or decrease
* melting point change; increase or decrease
& when does ph increase or decrease?

e.g adding more water does what, not by neutralization. 

thanks, acash09

WARRIOR:
An impure subsance melts at a rangge BELOW THE MELTING POINT
                            boils at a range  ABOVE THE BOILING POINT

 ph gr8er 7 is alkaline .....ph  less than 7 is acidic  .

adding more water just makes somethin more DILUTE ..means less acidic/or alkaline

J.Darren:

--- Quote from: Kimo Jesus on May 22, 2010, 05:55:15 pm ---An impure subsance melts at a rangge BELOW THE MELTING POINT
                            boils at a range  ABOVE THE BOILING POINT

 ph gr8er 7 is alkaline .....ph  less than 7 is acidic  .

adding more water just makes somethin more DILUTE ..means less acidic/or alkaline

--- End quote ---
Wait, I recall that back in 03 / 04 there is a reaction that involves Mg ribbon and acid, if you increase the volume of acid, the change in temp would decrease, same theory holds true for water, if it is a metal + water reaction, as we all know, salt and hydrogen is produced, yet the change in temperature would be smaller if greater volume of water is used. This is also a common question that appeared in Paper 6.

Kimo : Are you intended to compose a revision notes thingie for Physics P3 ?

WARRIOR:

--- Quote from: J.Darren on May 22, 2010, 07:11:29 pm ---Wait, I recall that back in 03 / 04 there is a reaction that involves Mg ribbon and acid, if you increase the volume of acid, the change in temp would decrease, same theory holds true for water, if it is a metal + water reaction, as we all know, salt and hydrogen is produced, yet the change in temperature would be smaller if greater volume of water is used. This is also a common question that appeared in Paper 6.

Kimo : Are you intended to compose a revision notes thingie for Physics P3 ?

--- End quote ---
if u mean chemistry paper 3  ..yep!

J.Darren:

--- Quote from: Kimo Jesus on May 23, 2010, 10:54:27 am ---if u mean chemistry paper 3  ..yep!

--- End quote ---
LOL my bad :D

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