Under what conditions, oxygen and hydrogen react with each other?

Which one of the following pairs of reactantas does not form oxygen when they react with each other ?

Under what conditions is Tyndal effect observed ?

Under what conditions is Tyndal effect observed ?

Under what conditions, is Boyle's law applicable?

Atomic hydrogen reacts with oxygen to give

Both the compounds 'A' and 'B' react with sodium metal to liberate hydrogen gas and react with each other to give Methylethanoate. The compound 'A' and 'B' are