Question

If heat of combustion of ethylene is 1411 KJ when a certain amount of ethylene was burnt 6226 KJ heat was evolved. Then the volume of O2 (at S.T.P.) that entered into the reaction is :-
(1) 296.5 ml
(2) 296.5 litre
(3) 6226 22.4 litre
(4) 22.4 litre​

Answer 1

Answer:

Explanation:

Given If heat of combustion of ethylene is 1411 KJ when a certain amount of ethylene was burnt 6226 KJ heat was evolved. Then the volume of O2 (at S.T.P.) that entered into the reaction is :-

We know that Δ h = 1411 kJ / mole  

Now 1411 KJ of energy is released by 1 mole of ethylene.

Therefore 6226 KJ of energy is released by 1 / 1411 x 6226  

                                                          = 6226 / 1411

                                                           = 4.412 moles of ethylene.

Now we know that 1 mole of ethylene uses 3 moles of oxygen

                                                     = 3 x 22.4

                                                  = 67.2 l of oxygen

Therefore 4.412 moles of ethylene uses = 67.2 x 4.412  

                                                                 = 296.49 litre of oxygen

                                                                 = 296.5 l