How would you balance this equation? h2co3 → co2 + h2o place a 2 in front of the co2. place a 2 in front of the h2co3 and h2o. add an o to the product side. it is already balanced.

H2CO3 → Co2  + H2O

The equation  is  already  balanced.

Explanation

The  equation is balanced since  the number of   each type of atoms  are   the same on the left side  and the right hand side.For instance  there is 2 H  atoms in reactant  side  and 2 H atoms on product side.Also  there   are 3 atoms of O  on  reactant side  and  3 atoms on product  side.In addition  there  is  1 C atom in reactant  side and  1 C atoms  on  product side.
Therefore the  equation is balance  since it  obey the law  of mass  conservation  which it  state that the mass  of reactant  side should be equal  to mass of product.

It's not the same dearthe first one is in grams per mole while the other is not