Question

A cylinder of cooking gas supplied by indian oil corporation is assumed to contain 14 kg of butane (∆hc for c4h10 = - 2600 kj mol-1 ). if a small family of three persons, requires 10,000 j of heat energy per day for cooking, the gas in the cylinder would last for

Answer 1

Molar mass of butane (C4H10) = 12x4 + 1x10 = 58g/mol

14kg = (14x1000)g = 14000g

Moles of butane = Given mass/molar mass
    
                           = 14000/58 
                           
                           = 241.38 moles


∆HC for C4H10 = - 2600 kj mol-1 

This means 1 mole of butane gives 2600kJ of energy

241.38 moles will give = 241.38 x 2600 = 627588 kJ

                                                               = 627,588,000 J

The number of days = 627,588,000/10,000
                 
                                 = 6262,758.8 days