thermal decomposition of CO2 and H2O

[michelborstrok]

Hello,

I had some questions because every website on the internet said something else:

At what temperature does CO2 decompose from CaCO2 and how long must it remain at this temperature?

 

 

for the next 3 questions, assume that the chemicals are around for some time enableing water to bind to the surface of the chemicals.

At what temperature does H20 decompose from SiO and how long must it remain at this temperature?

 

At what temperature does H20 decompose from Fe2O3 and how long must it remain at this temperature?

 

At what temperature does H20 decompose from AlO and how long must it remain at this temperature?

 

And is there also a good source a can use to find these kind of things?

 

thank you!

[Sensei]

Hello,

I had some questions because every website on the internet said something else:

At what temperature does CO2 decompose from CaCO2 and how long must it remain at this temperature?

According to

https://en.wikipedia.org/wiki/Calcium_carbonate

"At temperatures above 550 °C the equilibrium CO2 pressure begins to exceed the CO2 pressure in air. So above 550 °C, calcium carbonate begins to outgas CO2 into air."

"The table shows that this partial pressure is not achieved until the temperature is nearly 800 °C. For the outgassing of CO2 from calcium carbonate to happen at an economically useful rate, the equilibrium pressure must significantly exceed the ambient pressure of CO2. And for it to happen rapidly, the equilibrium pressure must exceed total atmospheric pressure of 101 kPa, which happens at 898 °C."

Read section "Calcination equilibrium"

 

for the next 3 questions, assume that the chemicals are around for some time enableing water to bind to the surface of the chemicals.

At what temperature does H20 decompose from SiO and how long must it remain at this temperature?

 

At what temperature does H20 decompose from Fe2O3 and how long must it remain at this temperature?

 

At what temperature does H20 decompose from AlO and how long must it remain at this temperature?

No. They don't decompose to water. Unless they're in hydrated form.

 

AlO, what is it?

Do you meant Al2O3 rather, or Al(OH)3?

 

And is there also a good source a can use to find these kind of things?

Wikipedia, page about compound, for a start.

Edited September 22, 2016 by Sensei

[michelborstrok]

Yes, i mean the hydrated forms, and yes i mean Al2O3 but i already found that one. The only one i need toknow is SiO.

I already found CaCO3 -> CaO + CO2 but there were many different temperatures on different websites. That was the reason I asked it here.