Which of the following shows a valid combustion reaction? 2al + 2o2 → 2alo + o2 c2h4 + 2o2 → 2co2 + 2h2o 2ch4 + o2 → 2co + 4h2 ca + o2 → caoh

Generally a combustion reaction is one in which a hydrocarbon burns completely in the presence of oxygen to form carbon dioxide and water. In other words, all the carbon's gets converted to CO2 while all the hydrogen's get converted H2O.

Thus, based on the given options reaction of ethylene with oxygen is a valid combustion reaction

C2H4 + 2O2 → 2CO2 + 2H2O

C2H4 + 2O2 → 2CO2 + 2H2O

Explanation:

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.