# Chemistry question !?!?! confused :S?

Calculate the enthalpy of reaction for the formation of anhydrous aluminum chloride 2 Al(s) + 3 Cl₂(g) ----> 2 AlCl₃(s) from the following data: 2 Al(s) + 6HCl(aq) ------> 2 AlCl₃(aq) + 3H₂ _________∆H= -1049kJ HCl(g) -------> HCl(aq)____________________________∆H= -73.5kJ H₂(g) + Cl₂(g)... show more Calculate the enthalpy of reaction for the formation of anhydrous aluminum chloride

2 Al(s) + 3 Cl₂(g) ----> 2 AlCl₃(s)

from the following data:

2 Al(s) + 6HCl(aq) ------> 2 AlCl₃(aq) + 3H₂ _________∆H= -1049kJ
HCl(g) -------> HCl(aq)____________________________∆H= -73.5kJ
H₂(g) + Cl₂(g) ---------> 2HCl(g)_____________________∆H= -185kJ
AlCl₃(s)---------> AlCl₃(aq)

a) -1399 kJ
b) 593.0 kJ
c) -1581 kJ
d) 1809.0 kJ
e) none of the above

I have literally spent over a half an hour on this question and still can't figure it out. Apparently the right answer is A, i just don't know how to get it. Could someone please walk me through this???

Thanks in advance
Update: the change of H for the last one is -323 kJ
2 answers 2