Chemistry Help?

Question

How much heat will be released if 6.0 grams of carbon reacts with excess oxygen according to teh equation below
C(s)+O2(g)-->CO2(g) enthalpy change is -34 kilojoules
would you times 6 g of C by (1 mol of C/12 g C)= ______ mol C

_____ mol C times (-190 kJ/1 mol C)= ______kJ
is that right, if it isn't could you correct me

Answer 1

Your unit for enthalpy change is incomplete. It should be kilojoules per mass, most likely moles.

6 g of C is 0.5 moles, which will produce 0.5 moles of CO2. Assuming that the enthalpy change is -34 KJ/mole, heat released will be 17 KJ.

Answer 2

where do you get the -190 kj7mol from?

If you have 6 g of C, you will have ca. 0.5 moles of C.

This will allow the reation to take place 0.5 mole times. This will create 0.5 mol * -34 kj/mol = -17 KJ for the system, which means, that there will be released 17 Kj of heat to the surroundings.

Answer 3

You haven't got one mole of C, you've got 6/12 = 1/2 mole of C.
So the enthalpy change is half of the value in the question.