Question

substance is oxidized and which is reduced. 1. 2K+2H2O_2KOH+H2

2. 2mg+O2_2mgo

3. 2Na+2H2O_2NaoH+H2

Answer 1

1. 2K+2H2O -------> 2KOH+H2

from right to left oxidation state of K is 0 to +1 means oxidised

so K get oxidised and H2O get reduced

2) 2Mg+O2 ------>2MgO

in the reactent Mg oxidaton state is 0

in the product Mg oxidation state is +2

in reactant O2 oxidation state is 0

in the product O oxidation state is -2

so Mg get oxidised and O2 get reduced

3)

2Na+2H2O -------> 2NaOH+H2

in the reactent Na oxidaton state is 0

in the product Mg oxidation state is +1

in reactant H oxidation state is +1

in the product H oxidation state is 0

Na get oxidised and

H2O get reduced