Indicate combustion products of hydrocarbons in excess of oxygen.

Let’s write the equations:
СН4 + 2О2 = СО2 + 2Н2О – combustion of methane, in excess of oxygen is accompanied by the release of carbon dioxide and water;
2С2Н6 + 4О2 = 4СО2 + 5Н2О – ethane combustion;
С3Н8 + 5О2 = 3СО2 + 4Н2О – propane combustion;
2С4Н10 + 13О2 = 8СО2 + 10Н2О – butane combustion;
Alkanes – methane, ethane, propane, butane are part of natural gas, participate in the combustion reaction, which is the basis for the use of their mixture as a fuel.
С5Н12 + 8О2 = 5СО2 + 6Н2О – combustion of pentane:
С6Н12 + 9О2 = 6СО2 + 6Н2О – hexane combustion;
С7Н16 + 11О2 = 7СО2 + 8Н2О – combustion of heptane;
2С8Н18 + 25О2 = 16СО2 + 18Н2О – octane combustion:
These reactions are exothermic; alkanes burn in an excess of oxygen with the release of carbon dioxide and water.