Are all combination reactions also redox reactions?

If not, please give an example. Thanks!

1 Answer
Dec 27, 2017

Nope .

Not all combination reactions are redox , some are however , like
#3Fe + 20_2 -> Fe_3O_4#
oxidation number of iron changed from 0 to #2 & 3# and for oxygen it changed from #0# to #-2#

but others are not

#CaO + H_2O -> Ca (OH)_2#
oxidation numbers of each element remain constant .
#Ca->+2#
#H->+1#
#O->-2#