Question

burning of natural gas is which chemical reaction

Answer 1

One molecule of methane, (the [g] referred to above means it is gaseous form), combined with two oxygen molecules, react to form a carbon dioxide molecule, and two water molecules usually given off as steam or water vapor during the reaction and energy. 

Answer 2

Yess it is because products like CO2 and H2O and heat/light are produced...

CH4+O2-CO2+H2O+Heat..☺