In the reaction C6H12 + __O2 → 6H2O + 6CO2, what coefficient should be placed in front of O2 to balance the reaction? 6 9 18 no coefficient is needed

The correct option is 9

Explanation:

The easiest way to balance any combustion equation is to first write the general form.  In a combustion reaction the products are always carbon dioxide (CO2) and water (H2O) and the reactants are the organic material plus oxygen (O2).

General Form:

C6H12 +  O2 -->   CO2  +  H2O

Now start by balancing the carbon atoms:

six carbons on the left so you need 6 on the right.

C6H12   +   O2   --->    6 CO2  +  H2O

Next balance the hydrogen atoms:

12 on the left, so you need 12 on the right.

C6H12  +   O2 -->   6CO2    +   6H2O

Now count the number of oxygen on the right = 12 + 6= 18

Divide the number on the right by 2 to get the number needed on the left.   18/2 = 9

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).