What is the balanced equation when Co2 gas reacts with water?

it is most likely carbonic acid, CO2 + H2O = H2CO3 The way to balance an equation is to figure out whether the number of atoms on one side of the = sign is the same as on the other side. So we’ve got one C, 2Hs, and 3Os on both sides. Making it balanced.

but cjscoot is right, it could be other things, for example, photosynthesis is the combination of carbon dioxide, water and energy and it produces glucose (this is just something you have to know, it isnt something you can figure out)

CO2 + H2O + Energy = C6H12O6 + O2

So lets balance this equation, (I always start on the right side). There’s 6 Cs. So we put a 6 infront of the CO2

6CO2 + H2O + Energy = C6H12O6 + O2

There’s 12 Hs. So we put a 6 infront of the H2O (since there’s 2 Hs per H2O, 6 x 2 = 12)

6CO2 + 6H2O + Energy = C6H12O6 + O2

Now we count. On the left, 6Cs, 18 Os, 12 Hs. On the right 6Cs, 8Os, 12 Hs

So we need 18 Os on the right. If we add it to the glucose it would mess everything up. So lets add it to the O2. If we put a 6 infront of it, it would total 18Os

6CO2 + 6H2O + Energy = C6H12O6 + 6O2

And we do the counting thing again Left = 6Cs, 18 Os, 12 Hs Right = 6Cs, 18 Os, 12 Hs

And we have a balanced equation