G2 Gas Fitter Practice Exam

How much air is required to burn 1000 cubic feet of natural gas per hour?

1. 5,000 cu ft

2. 10,000 cu ft

3. 15,000 cu ft

4. 20,000 cu ft

The correct answer is: 10,000 cu ft

In order to understand how much air is required to burn natural gas, it’s essential to know the combustion process for this type of fuel. Natural gas primarily consists of methane (CH4), and the complete combustion of methane typically follows the reaction: \[ CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O \] This equation shows that one molecule of methane requires two molecules of oxygen for complete combustion. Given that the air we breathe is composed of approximately 21% oxygen and 79% nitrogen, the volume of air needed can be calculated based on the oxygen requirement. Generally, for complete combustion of natural gas, the stoichiometric air requirement is about 10 times the volume of natural gas. Therefore, if you have 1000 cubic feet of natural gas, you would typically require about 10,000 cubic feet of air to ensure complete combustion. This calculation reflects correct combustion principles and ensures that enough air (which includes the necessary oxygen) is provided for the gas to burn effectively. Hence, for the question regarding the air requirement for burning 1000 cubic feet of natural gas per hour, the answer aligns perfectly with the standard combustion principles, resulting in 10,000 cubic feet of