Which coefficients correctly balance the formula equation cao + h2o ® ca (oh) 2?

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