[Ahmed Abdullah]

One mole of certain gas is confined in a container. Suppose every molecule has decomposed and given rise to- two new molecules. Let's assume (for this purpose ) it requires negligible amount of energy for the molecule to decompose (or not any energy at all). So what will we observe?
The amount of matter has been doubled by the process, so pressure should increase- that's obvious. What happens to the temperature?
Does it stay the same OR increase?
Once I thought it should increase but the ideal gas formula seems to suggest the other.
Here
R/V=P/nT=constant (from PV=nRT)

when n increase P tends to increase and T tends to decrease to keep R/V a constant.
It is also possible that Temperature increase and so pressure increase -..But this time pressure should increase high for it is pushed up by both increase in Pressure and Temperature.
Please help me

[Ahmed Abdullah]

I think I have got it. If the two newly formed molecules have the same mass then the pressure should not increase rather the temperature is halved. It is because temperature is something proportional to kinetic energy. . When a molecule is splitted to two new similliar molecule then the energy is divided between them each having halve of the original (energy is conserved). So temperature falls nothing happens to pressure.
Am I right? Please comment.