The reaction taking place when butane burns to produce a flame is a combustion reaction. Combustion reactions involve the rapid oxidation of a fuel (in this case, butane) in the presence of oxygen, releasing energy in the form of heat and light.

During the combustion of butane, the hydrocarbon molecules react with oxygen molecules, breaking the carbon-carbon and carbon-hydrogen bonds in the fuel and forming new bonds between carbon and oxygen atoms. This results in the formation of carbon dioxide (CO2) and water (H2O) as the main products of the reaction.

The chemical equation for the balanced combustion reaction of butane is:

C4H10 + 6.5O2 -> 4CO2 + 5H2O + energy

This equation indicates that one molecule of butane reacts with 6.5 molecules of oxygen to produce four molecules of carbon dioxide, five molecules of water, and a significant amount of energy released as heat and light.

The energy released during the combustion of butane makes it a valuable fuel for various applications, such as cooking, heating, and powering vehicles. However, it's crucial to ensure proper ventilation and safety measures are taken when using butane as improper handling or combustion can lead to hazardous situations.