Question

Is there enough energy in a Bic lighter (5 g of butane) to heat the water in a 500 ml water bottle to boiling, and to boil all the water? If not, how many lighters are required to heat and boil all the water?Assume the water is initially at 25 C, and the density of water is 1g/ml.

Answer 1

Enthalpy of combustion of butane, ΔcHo = –2877.5 kJ/mol

no of mol of butane in Bic lighter = 5/58 = 0.086 mol

amount of energy given by one Bic lighter = 0.086*2877.5 = 247.465 kj

now,

amount of energy required to boiling = m*s*DT + n*DHvap

            = 500*4.184*(100-25) +(500/18)*40.7*10^3

            = 1.287*10^6 joule

            = 1.287*10^3 kj

            = 1287 kj

so that, 1 Bic lighter = 247.465 kj

        no of Bic lighter required = 1287/247.465 = 5.2

it will be almost 5 Bic lighter required.