[Blag007]

My son asked me the following question, and I didn't know the answer, so I'm hoping to get the answer here.  Question: if you just put hydrogen and oxygen into a container, would water molecules form or is more required?  I realize this may be a basic question for people here, but I sure would appreciate your help.  Thank you.

[vhpk]

My son asked me the following question, and I didn't know the answer, so I'm hoping to get the answer here.  Question: if you just put hydrogen and oxygen into a container, would water molecules form or is more required?  I realize this may be a basic question for people here, but I sure would appreciate your help.  Thank you.

I suppose not. If the mixture of two gas above in the rate of 2:1 respectively, it wil explode. However, people daren't do this. Furthermore, for the reaction takes place, high temperature or high current is required since the bond O=O is rather more stable than O-H.

[Yggdrasil]

No.  All chemical reactions have an activation energy; that is, there is an energetic barrier to the reaction and you have to put in some energy to overcome this barrier.  Thermal energy at room temperature would not be sufficient to get hydrogen and oxygen to react, but if you added a spark, you could overcome the barrier and get them to react.

The situation is analogous to starting a fire.  For a fire, you need fuel (hydrogen), air (oxygen), and an ignition source (something like a spark to provide the necessary activation energy).  This is also why things like gasoline and wood do not spontaneously combust.

[Blag007]

Thank you both for your answers and that there needs to be the equivalent of some sort of spark to cause the reaction between oxygen and hydrogen to form water.  This will be enough info to satisfy my son's question - I appreciate your answers!

[P]

Thank you both for your answers and that there needs to be the equivalent of some sort of spark to cause the reaction between oxygen and hydrogen to form water.  This will be enough info to satisfy my son's question - I appreciate your answers!

As Yggdrasil said:

The situation is analogous to starting a fire.  For a fire, you need fuel (hydrogen), air (oxygen), and an ignition source (something like a spark to provide the necessary activation energy).  This is also why things like gasoline and wood do not spontaneously combust.

Basically, if you burn Hydrogen in oxygen (or air) the result is water.