saps - 8-3-2005 at 18:12
Does anybody know nything about the exothermic reaction created when certain oxides (eg. sodium oxide) become hydroxides
runlabrun - 8-3-2005 at 19:01
Its very exothermic....
What specifics do you want to know? the literal data values? you need to ask a direct question..
Texts and some online sites have tables of info on data values. Check librarys if cant be found online
-rlr
saps - 10-3-2005 at 14:27
could u estimate the tempuratures at which the reaction w/ calium oxide, magnesium oxide, and sodium oxide would reach?
mick - 11-3-2005 at 15:10
I would think calcium oxide would get warm similar to adding water to cement. Magnesium oxide would not be as warm but sodium oxide might be a lot
warmer
mick
chemoleo - 11-3-2005 at 15:43
Well obvioulsy the reaction will never top 100 deg C if the oxide is added to an excess of H2O.
If much smaller amounts of water are used, i.e. drop by drop, then the temperature might top 100deg C. Again this depends very much however on the
mixing time, the coarseness etc of the oxide, how fast H2O is evaporated off, etc... Plenty of variables.
Unfortunately, even the total heat released (which could be measured by calorimetry) does not necessarily relate to the initial temperature spike,
i.e. a very fast reaction will produce a greater temp, while the total heat given off may still be lower than the one of a reaction that is more
exothermic.
In other word it depends on the reaction constants (how fast do things react), and the energy released per mole, and on the dispersion, initial oxide
properties and so on that determine the final maximum temperature.
But I agree with mick nonetheless, I should thnk that Na2O reacts a lot more exothermically than CaO. THe reverse reaction, i.e. 2NaOH --> Na2O +
H2O requires a lot more heat than Ca(OH)2 --> CaO + H2O, explaining why the reaction Na2O + H2O is more energetic than that with CaO.