How much heat is either ______(absorbed or given off) when 91.45g of HI decomposes to H2 and I2 at 25 degrees C?

Question

What goes in the blank and how much heat?

Thanks!

Answer 1

dH = delta H
dHrxn = (n*dHf products) - (n*dHf reactants)
dH rxn will tell you the value of dH. - means heat given off; + means heat absorbed.