If you were to light a match in a sealed room containing pure hydrogen and nothing else, the match would ignite the hydrogen gas. Hydrogen is highly flammable, and when exposed to an ignition source like a match, it combines with oxygen in the air to undergo a chemical reaction called combustion.
The combustion of hydrogen in the presence of oxygen produces a flame. The reaction can be represented by the equation:
2H₂ (g) + O₂ (g) → 2H₂O (g)
In this reaction, hydrogen gas (H₂) combines with oxygen gas (O₂) to form water vapor (H₂O) as the product. The release of energy during this reaction is what sustains the flame.
In the case of a sealed room with pure hydrogen, the combustion of hydrogen would continue until all the hydrogen is consumed or the oxygen supply is depleted. This would result in the formation of water vapor, which would gradually fill the sealed room.
It's important to note that hydrogen gas is highly flammable and can create explosive conditions if not handled properly. This is why precautions should always be taken when working with hydrogen or any other flammable gases.