Chemistry yeeelp!?

Question

is this statement true H2(g)+Cl2(g)-->no reaction if so why? why not?

Answer 1

Both hydrogen and chlorine are very reactive. The would form HCl because it is more stable than H2 or Cl2.

Answer 2

At room temperature and pressure, it's true.

Every reaction has to overcome an energy barrier to occur (called the activation energy). At room temperature and pressure there is no incentive for the compounds to combine. Add some heat (or even a spark) and the Cl2 will act like a strong oxidizing agent and should be able to combust the hydrogen and release a lot of heat. The byproduct of that would be HCl gas.

The other way to lower an activation energy barrier is to use a catalyst.

While it is very true that the thermodynamically stable product would be HCl, the kinetic (the rate of reaction) at room temperature with no catalyst is so slow that the reaction is not observed. This is true with most combustion reactions. Does gasoline + air = CO2 and water spontaneously? No, not at room temperature and pressure without a catalyst. If you give that system enough energy to overcome the activation energy (a spark) then the reaction will occur and the generated heat will speed up the reaction even further! Even though the thermodynamically stable products are CO2 and water they can co-exist peacefully (until the activation energy level is met, then kaboom!).

good luck!