Question

balance
the
following
equation. CO2 +H2O- C6H12O6+O2
​

Answer 1

Answer:

If you look at the equation backwards it reminds you of oxidation (burning) of a carbohydrate:

C6H12O6+O2=CO2+H20.

That is a reaction that will go on on its own, once you give it a little push, much like a rock rolls downhill.

You are trying to write how a plant will use carbon dioxide and water to make sugars. That reaction requires energy to proceed at all (like pushing a rock uphill). Plants get the needed energy from the sun.

To balance the backwards equation,

C6H12O6 + O2 = CO2 +H2O,

I first count the carbon atoms on both sides. There are 6 in C6H12O6, on the left side, so I write a 6 before CO2 to have 6 atoms of carbon on the other side.

Then I count the hydrogen atoms. There are 12 in C6H12O6, so I write a 6 in front of H2O, to have 12 hydrogen atoms on the other side. That leaves me with

C6H12O6 + O2 = 6CO2 + 6H2O so far.

Now I count the oxygen atoms on both sides. On the right side, there are 6×2=12 in the 6CO2 part, and 6 in the 6H2O part, for a total of 12+6=18 oxygen atoms.

On the left side there are 6 oxygen atoms in the C6H12O6 part,

I need 18-6=12 more, and I can get them by placing a 6 in front of O2.

Now I have

C6H12O6 + 6O2 = 6CO2 + 6H2O , and the number of atoms of each kind is the same on both sides of the = sign. The equation is balanced. So is the reversed equation

6CO2 + 6H2O = C6H12O6 + 6O2 .

We do not write H2O (water) on both sides. I could add the same amount of water on both sides, but it “cancels out”.