When one gram of gas, is burned, 55.5kJ of heat are released. How many pounds of methane gas must be burned to release 2.578 x 10^3kJ of heat?

Answer 1

CH4 + 2O2 ==> CO2 + 2H2O + heat

So you get 55.5 kJ for 1 gram CH4.
You want how many grams to produce 2578 kJ.
1 gram x (2578/55.5) = ? grams CH4 required. Convert that to pounds.