Question

Δh = -296 kj/mol (a) how much heat is evolved when 585 g sulfur is burned in excess o2

Answer 1

You're given Δh in terms of kJ/mol, so you need to convert mass of sulfur to moles of sulfur using its molar mass: 585 g / 32 g/mol = 18.28 mol.

Now you can find total heat using the given enthalpy of combustion:

q = Δh * n
q = -296 kJ/mol * 18.28 mol
q = -5411 kJ

The negative indicates 5411 kJ of heat were released from the system.