THE HEAT OF COMBUSTION OF METHANE IS -50.38 KJ /MOL . HOW MANY MOLES OF METHANE MUST BE BURNT IN ORDER TO PRODUCE 137KJ
MM[METHANE]=16.04NG/MOL
You get 50.38 kJ from 1 mol CH4 so you will need
1 mol x 137/50.38 = ? mols CH4 needed.
If you want to convert to grams, but that isn't the question, grams CH4 = mols CH4 x molar mass CH4 = ?
so why don't you put the negative in your answer @DrBob222
To find out how many moles of methane must be burned to produce 137 kJ of heat, we need to use the heat of combustion of methane and the given value for the heat produced.
The given heat of combustion of methane is -50.38 kJ/mol, which means that when one mole of methane is burned, it produces -50.38 kJ of heat. Since the value is negative, it indicates that heat is released during the combustion.
We have to find the moles of methane burned to produce 137 kJ of heat. Let's set up the proportion:
(-50.38 kJ/mol) / (1 mol of methane) = (137 kJ) / (x mol of methane)
Cross-multiplying gives us:
-50.38 kJ * x mol of methane = 1 mol of methane * 137 kJ
Solving for x:
x mol of methane = (1 mol of methane * 137 kJ) / (-50.38 kJ)
x mol of methane = -2.72 mol
Since we can't have a negative number of moles, the answer would be approximately 2.72 moles of methane must be burned to produce 137 kJ of heat.