Question

10 ml of hydrocarbon gives 30 ml of co2. it requires 40 ml of o2 for complete combustion. find molecular formula of hydrocarbon.​

Answer 1

Explanation:

the ratio is 1:3:4

all the Carbon from the hydrocarbon is in the CO2 

10 ml of hydrocarbon produces 30 ml CO2, 

1 : 3 ratio 

So 1 mole hydrocarbon has 3 moles Carbon 

All the H ends up in the water 

10 ml hydrocarbon produces 50 ml water, 

1 : 4 ratio, 

but also each water has 2 H atoms 

So 1 mole hydrocarbon has 10 moles Hydrogen 

which gives 

C4H10 

You can balance an equation for combustion of C3H10 to check the answer 

C4H10 + 13/2 O2 --> 3CO2 + 4H2O