A vessel at 1000 K contains CO₂ – what happens to it at high temperature?

At very high temperatures like 1000 K, carbon dioxide (CO₂) can undergo thermal dissociation.

The reaction is:
CO₂ ⇌ CO + 1/2 O₂

Key explanation:

• At high temperature, the stability of CO₂ decreases
• Some CO₂ molecules break down into carbon monoxide (CO) and oxygen (O₂)
• This is a reversible reaction and reaches equilibrium

Important points:

• The extent of dissociation increases with temperature
• The reaction is endothermic, meaning it absorbs heat
• Not all CO₂ decomposes; only a small fraction dissociates at 1000 K

Thus, at high temperatures, CO₂ partially decomposes into simpler gases.