dry methane is burned with dry air. both are at 25C initially. the adiabatic flame temperature is 1300C. if complete combustion is assumed, how much excess air is used?

To solve this problem, we need to use the concept of stoichiometry and the adiabatic flame temperature.

1. Write down the balanced chemical equation for the combustion of methane:

   CH4 + 2O2 -> CO2 + 2H2O

2. From the stoichiometry of the reaction, we can see that one mole of methane reacts with two moles of oxygen. This is the theoretical amount of oxygen needed for complete combustion.

3. The adiabatic flame temperature is the temperature that would be achieved by a flame in the absence of heat loss to the surroundings. In this case, it is given as 1300C.

4. The amount of excess air used can be determined by comparing the actual amount of air used in the combustion to the theoretical amount.

5. However, the problem does not provide information on the actual amount of air used in the combustion. Therefore, it is not possible to calculate the amount of excess air used based on the information provided.

In order to solve this problem, we would need additional information such as the actual amount of air used in the combustion or the composition of the combustion products.