Question

An unknown hydrocarbon CxHyOz produces 300ml of CO2 and 300ml of H20 per 50ml of hydrocarbon. What is the formula of hydrocarbon

Answer 1

Dear Student
The general combustion reaction for hydrocarbons containing O is as follows
C_xH_yO_z + (x+y/4 -z)O₂ ------> xCO₂ + y/2 H₂O
Now 300 ml of CO₂ and 300ml of H₂O are being produced per 50 ml of hydrocarbon
It means 6 moles each of C_{​​​​​​}O₂ and H₂​​​​​​​O re being produced per mole of hydrocarbon as 6 times the volumes are being produced.
hence the reaction can be written as
C_xH_yO_z + (x+y/4 -z)O₂ ------> 6CO₂ + 6H₂​​​​​​​O
Comparing with general equation
x = 6
y/2 = 6; y = 12
Now total O on left side = z + 2 (x+y/4 -z) = z + 2(6+3-z) = 18-z
Total O on right side = 12
18 - z = 12
z = 6
Therefore molecular formula of compound is C₆H₁₂O₆
​​​​​​​Regards