When 0.442g of sodium metal is added to an excess of HCl acid, 4590J of heat are produced. What is the enthalpy of the reaction as written:
2Na(s) + 2HCl (aq) yields 2NaCl + H2(g)

What is enthalpy of reaction in KJ.

I tried to work this out but am not sure if I need to multiply my answer by two because of the 2 moles of Na or if that is accounted for already in the grams of sample.
My work as far:
chemical reaction is exothermic, so delta H wil be negative
Q=number of moles x delta H
There are 2 moles of Na in equation producing 2 mol NaCl
Na is 22.989769 g/mol so 0.4429 sample has .4429/22.989769 = 0.019 mol
Delta H is Q/number of moles
-4590J/.019mol = -241,578.9J divided by 1000 is -241.579KJ. (enthalpy)
So I wonder if I need to multiply this by 2 since the chemical equation has two moles
if so, the answer would be -483.158KJ.
IF I'm not using the correct formula to solve, I also need to know that.



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