# What type of reaction is 2C_4H_20(g) + 13O_2(g) -> 8CO_2(g) + 10H_2O(g)?

Chimaerical? There is no hydrocarbon with a ${C}_{4} {H}_{20}$ formula.
The saturated 4 carbon hydocarbon is butane, ${C}_{4} {H}_{10}$. I think you are quite capable of representing its combustion.