CaO + H2O → Ca(OH)2
the number of O atom on the left side is 1 and on the right side 2 so,
we put 2H2O instead of H2O
CaO + 2H2O → Ca(OH)2
now we have to put 2Ca(OH)2 instead of Ca(OH)2 to make H atoms equal on both sides 4
CaO + 2H2O → 2Ca(OH)2
now we have to put 2CaO instead of CaO to make Ca atoms equal on both sides 2 atoms.
∴ the final balanced equation is:
2CaO + 2H2O → 2 Ca(OH)2
∴ the coefficients are 2 2 2
