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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: Implore01 on September 17, 2013, 06:49:08 pm

Title: Implore01's Chemistry Question Thread
Post by: Implore01 on September 17, 2013, 06:49:08 pm: Why is CaCO3 calcium carbonate considered a base? I did this a while ago, but I have forgotten already :( Isn't base a hydrogen acceptor according to the Bronsted Lowry Theory?
Title: Re: Implore01's Chemistry Question Thread
Post by: Alwin on September 17, 2013, 06:54:16 pm: Quote from: Implore01 on September 17, 2013, 06:49:08 pm
Why is CaCO3 calcium carbonate considered a base? I did this a while ago, but I have forgotten already :( Isn't base a hydrogen acceptor according to the Bronsted Lowry Theory?

HA is an acid and M₂CO₃ a metal carbonate:

$2HA (aq) +M_2 CO_3 (s) \rightarrow 2MA (aq) + CO_2 (g) + H_2 O (l)$

Play spot the acid/conjugate base and base/conjugate acid to "prove" how it is a acid-base reaction... and a metal carbonate can act as a base
Title: Re: Implore01's Chemistry Question Thread
Post by: Implore01 on September 17, 2013, 06:57:48 pm: so it's an exception to the rule that bases are proton acceptors?
Title: Re: Implore01's Chemistry Question Thread
Post by: SocialRhubarb on September 18, 2013, 05:12:06 pm: It still accepts protons.

You can kind of view it as the carbonate ion, $CO_3^{2-}$ , accepting 2 hydrogen ions to become $H_2CO_3$ , which is unstable so decomposes to form $H_2O$ and $CO_2$ .