What happens when a gas molecule hits fire?

Answer 1

Let's change this: what happens when gas hits fire? One molecule isn't enough to do anything.

A fire needs three things to burn: fuel, oxygen and heat.

If you hit a fire with a gas, one of three things can happen to the fire, depending on what gas you used.

If you used a fuel gas, the flame will increase in size if there is enough additional ambient oxygen to react with the added fuel. (If your fire is in free air, there will be.) What happens to the molecule depends on what specific fuel gas it is. If you're burning hydrogen, it will combine with oxygen and become water. If you're burning a hydrocarbon, it will split up; the carbon will become CO2 and the hydrogen will become water. If you use inorganic fuels - ammonia and hydrogen peroxide are both flammable - you will get whatever reaction product that molecule will give you.

If you used oxygen, the flame will also increase in size. Oxygen itself is not flammable, but fires require oxygen to burn so adding oxygen will make the fire burn better.

If you used a nonflammable gas like carbon dioxide, it can do several things. It could shield the flame from oxygen or cool it, either of which will put the fire out.

Answer 2

When a gas molecule hits fire, it can undergo combustion if it is flammable. The gas molecule interacts with the heat and oxygen present in the fire, leading to a chemical reaction that releases energy in the form of heat and light. This process is often accompanied by the production of new compounds and a change in the state of the gas molecule.