Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: hipbear on February 28, 2010, 04:00:06 AM
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Hello I am having a lot of trouble with this question. I do not really understand what conditions will contribute. I have answered them but I really am unsure if I am even answering the question correctly. Any help would be appreciated. Thanks.
The balanced chemical equilibrium equation to show the formation of the calcium carbonate solid in limestone caves is CO2(g) + H2O(l) + CaCO3(s) --> Ca2+(aq) + 2HCO3(aq)
Use Le Chateliers principle to predict what conditions would contribute to;
i.) The formation of more CaCO3(s)
(My Answer)
1. Increase in volume of the container
2. Increase in temperature
3. Adding more HCO3(aq)
ii.) The decomposition of the CaCO3(s)
(My Answer)
1. Reducing the volume of the container
2. Decreasing the temperature.
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Why do you think changing voulme of the container will change anything? (note: this is not a trick question, answer just as you think).
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This is what I know about volume of the container
CO2(g) + H2O(l) + CaCO3(s) --> Ca2+(aq) + 2HCO3(aq)
If you increased the pressure, which is the same as decreasing the volume, the reaction will shift to the side with fewer moles. In this case to the products side.
If you decrease the pressure, increase the volume, the reaction will shift to the side with a greater number of moles. In this case the reactants. I thought if more CaCO3 was created then there would be more formation of CaCO3??
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Volume and pressure are related, so you are not completely off, but if you mean change in pressure - write it. Changing volume is ambiguous as long as you have not stated precisely if you mean closed vessel.
i.) The formation of more CaCO3(s)[/b]
(My Answer)
1. Increase in volume of the container
Let's see - increasing volume means lowering the pressure. That means more 'place' for gaseous products - does it mean more solid CaCO3, or more products of decomposition?