Home >
Community >
Reaction of sulphur with calcium carbonate
Upvote
33
Downvote
+ Enthalpy
+ Chemistry
Posted by
Marcus Moore
Reaction of sulphur with calcium carbonate
If you mix CaCO3 + S and heat the mix, the first thing to occur will be that sulfur melts. Second, CaCO3 loses CO2 and becomes CaO. Third, sulfur boils off (or has already boiled off).
A thought that perhaps CaS + O2 would form can be eliminated on the basis that roasting metal sulfides in air produces SO2 + the metal oxide. So the metal sulfide is unlikely.
If any reaction had a possibility, it might be 3 CO2 + S --> 3 CO + SO3, but the heats of formation favor 3 CO2 + S by a large margin. The heat of formation of SO3 is about the same as CO2, and the heat of formation of SO2 is even less.
If you mix CaCO3 + S and heat the mix, the first thing to occur will be that sulfur melts. Second, CaCO3 loses CO2 and becomes CaO. Third, sulfur boils off (or has already boiled off).
A thought that perhaps CaS + O2 would form can be eliminated on the basis that roasting metal sulfides in air produces SO2 + the metal oxide. So the metal sulfide is unlikely.
If any reaction had a possibility, it might be 3 CO2 + S --> 3 CO + SO3, but the heats of formation favor 3 CO2 + S by a large margin. The heat of formation of SO3 is about the same as CO2, and the heat of formation of SO2 is even less.
If you wind up with CaO and S (all the CO2 is gaseous and gone), It might be possible to arrange conditions where an excess of sulfur takes the oxygen from CaO and gives CaS + SO2. If you can remove all the SO2 produced, any equilibrium would leave you with CaS. Individual bond energies are not as significant as heats of formation of a compound. Bonds are only parts of a compound.More
But if the final products are CaO, CO2 and S, then why wouldnt sulphur reduce calcium oxide to calcium as the bond energy of 3(Ca-O) is far less than that of 3(S=O). (3CaCO3 + S ->Ca + SO3 + 3CO2)More
If you mix CaCO3 + S and heat the mix, the first thing to occur will be that sulfur melts. Second, CaCO3 loses CO2 and becomes CaO. Third, sulfur boils off (or has already boiled off).
A thought that perhaps CaS + O2 would form can be eliminated on the basis that roasting metal sulfides in air produces SO2 + the metal oxide. So the metal sulfide is unlikely.
If any reaction had a possibility, it might be 3 CO2 + S --> 3 CO + SO3, but the heats of formation favor 3 CO2 + S by a large margin. The heat of formation of SO3 is about the same as CO2, and the heat of formation of SO2 is even less.
So the final products will be CaO + sulfur + CO2.
If you mix CaCO3 + S and heat the mix, the first thing to occur will be that sulfur melts. Second, CaCO3 loses CO2 and becomes CaO. Third, sulfur boils off (or has already boiled off).
A thought that perhaps CaS + O2 would form can be eliminated on the basis that roasting metal sulfides in air produces SO2 + the metal oxide. So the metal sulfide is unlikely.
If any reaction had a possibility, it might be 3 CO2 + S --> 3 CO + SO3, but the heats of formation favor 3 CO2 + S by a large margin. The heat of formation of SO3 is about the same as CO2, and the heat of formation of SO2 is even less.
So the final products will be CaO + sulfur + CO2.
More
VOTE
VOTE
VOTE