Question

2 c₂h₆(g) + 7 o₂(g) → 4 co₂(g) + 6 h₂o(l)
○ synthesis
○ decomposition
○ single displacement
○ double displacement
● combustion

Explanation:

This reaction involves a hydrocarbon ($\text{C}_2\text{H}_6$, ethane) reacting with oxygen gas to produce carbon dioxide and liquid water, which fits the definition of a combustion reaction—an exothermic reaction where a fuel reacts with an oxidant to form oxide products. Synthesis reactions combine simple substances into a complex one, decomposition breaks a compound into simpler ones, single displacement involves one element replacing another in a compound, and double displacement involves swapping of ions between two compounds, none of which match the given reaction.

Answer:

Combustion