Daave

agreed - definitely a lost P.E. teacher - BenSon is right, any substance will decompose given enough heat, the temperature at which this will occur is dependant on various things including the strength of the intra-molecular bonds and the distance of the valence electrons from the nucleus.

Sodium carbonate decomposes somewhere above 851 degrees celcius.

I do not need to prove that a carbonate will separate into it's oxide and carbon dioxide - but that the carbonates further down the periodic table are easier to decompose than those higher in the periodic table i.e. Calcium carbonate decomposing more easily than Sodium carbonate.

AH yes - I got it the wrong way round - the actual hypothesis I had to test experimentally is: "that the ease of decomposition of carbonates is in the reverse order of the Periodic Table" that being from easiest to most difficult, not the way around - as I had initially interpreted it. When heating it (at such high temperatures), what would be the best way to collect the carbon dioxide let off? Or again - as I asked in my original post - is there some easier way to do it?

I'm Daave and I've just started studying Chemistry, Physics and Mathematics for my 2nd last year of high school here in Sydney, Australia. I'm finding chemistry most interesting - but never turn down a good math problem.

As we look at the metals on the periodic table, the further we go along, the more difficult that metal's carbonate is to decompose. i.e. Sodium Carbonate is more readily decomposed than Calcium Carbonate. I need to devise a method of experimentally testing this. My thoughs as such are; we heat the carbonate (as a solid - possibly in water [but NOT aqueous]), and using limewater - test at what temperature carbon dioxide is released. My question is - is this approach feasible, what equipment will I need, is there a better way of proving the hypothesis. I have access to varoius carbonates, limewater, and ordinary lab equipment (glassware, bunsens, filtration devices, etc) Any suggestions?