Question

the combustion of butane produces heat by the following reaction :2 C4H10 +13O2 -----8 CO2+10 H2O.DH= -5314 KJ/mol.How many grams of butane must be heated to produce 1x104KJ of heat

Answer 1

Clearly from the stochiometric equation it's clear that
2 moles of butane will produce - 5314 kJ
So
1 mole of butane will produce - 5314/2= - 2657kJ of heat

Now. No: of moles of butane required for producing 1x10^4 kJ heat is given as
Number of moles = 10^4/2657=3.76 moles of butane.

1 mole butane = 58g
3.76 mole butane =58x3.76=218.2g