Posted by Tanisha on Saturday, September 7, 2013 at 7:41am.
If 23.7g of C8H18 are combusted, what mass of water will be produced?

Chemistry  MathMate, Saturday, September 7, 2013 at 8:08am
First establish the combustion equation and have it balanced:
C_{8}H_{18} + O_{2} > 8CO_{2} + 9H_{2}O.
Balances for C, but not for O.
Since there are 16+9=25O on the right, we need to double the number to make the number of molecules on the left a whole number. So it becomes:
2C_{8}H_{18} + 25O_{2} > 16CO_{2} + 18H_{2}O.
Next step is to observe the relative molecular masses in _{8}H_{18} and 18H_{2}O.
You can then calculate the mass of H_{2}O produced by proportions using 23.7g of octane.