[slu1986]

What mass of CH4 (g) must be burned to release 334 kJ of heat to the surroundings?

         CH4 (g) + 2 O2 (g) --------> CO2 (g) + 2 H2O (l)   ΔH°= -890 kJ

I know the answer is 6.00 g, but I have no idea how to set up the problem to get that answer.  If someone could please guide me in the right direction on how to set up the problem, that would be great. 

[Borek]

From your reaction equation it is obvious that 1 mole of methane releases 890 kJ. Half mole releases 445 kJ (890 kJ/2) and so on. How many moles to release 334 kJ? What is mass of these moles?

[slu1986]

This is how I set up the equation: -334 kJ * 1 mol CH4/-890 kJ * 16.04 g CH4/ 1 mol CH4 = 6.01 g CH4
My choice of answers has 6.00 g CH4 and thats the correct answer.  Did I solve it right?

[enahs]

Yes.