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

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.