Question

Question #16993

Answer 1

`"CH"_3"CHO" +5/2"O"_2 ->2"H"_2"O" + 2"CO"_2`

Explanation:

Because it's a combustion reaction, there must be oxygen reacting with the acetaldehyde `("O"_2)`.

Then it forms water and carbon dioxide.

Because there are two carbon atoms in the aldehyde, there'll have to be 2 mol of carbon dioxide.

Then balance the H's by putting a 2 in front of the water molecule.

Now balance the O's - you have 2 in the `"H"_2"O"` molecule and 4 in the `"CO"_2`, a total of 6, and one in `"CH"_3"CHO"` on the other side - so you need 5 more on the LHS. `:.` multiply the `"O"_2` by `5/2`