Hydrogen as reducing agent: hydrogen donates its electrons to areduce other substances.
Examples:
•hydrogen reduces acetylene(OS= -1)to ethane(OS= -3).
C2H2+2H2--->C2H6.
•hydrogen reduces bromine(OS=0)to hydrobromic acid(OS=-1).
H2+Br2---->2HBr.
•hydrogen reduces oxygen(OS= 0 )To water (OS= -2).
2H2+O2---->2H2O.
