HOW DO YOU CALCULATE THE standard enthalpy change in kJ? PLEASE HELP?

Question

Im Stumped with this problem:

Calculate the standard enthalpy change in kJ for the production of 14.6 g of Fe(s) from a reaction where the reactants and products are:

reactants: Fe2O3 (s) CO (g)

products: Fe(s) CO2 (g)

Answer 1

okay, i can't seem to get a balanced equation..if you get that..use Hess's Law

[sum of heat of formation of products] - [sum of heat of formation of reactants]

i'm gonna give you an example jus in case

2XZ + 3YS --> 4ZI + O2(g)

according to hess's law, heres wat you do:

[4 moles (heat of formation of ZI) + 1 mole (0 kJ/mol)] - [2 moles (heat of formation of XZ) + 3 moles (heat of formation of YS)]

remember, elemental thingys dont have a heat of formation

after you get that number, use basic stoich to calculate how much heat is given off for that particular amount of iron

YAY reaction is here:

Fe2O3(s) + 3CO(g) -> 2Fe(s) + 3CO2(g)

let's follow hess's law

[2 moles (0 kJ/mol) + 3 moles (-110.5kJ/mol)] - [1 mole (-824.2kJ/mol) + 3 moles (-393.5kJ/mol)]

that gives you = 1673.20 kJ for 2 moles of iron

so that's 836.60 kJ/mol of Fe

so let's do basic stoich

14.6 g (mol/55.85g) (836.6 kJ/mol) = 219 kJ of heat is taken in, since it's a positive value (endothermic reaction)

Answer 2

How can you be so stupid? Use a enthalpy kj calculator with a stump deletion button. duhhhh.

Answer 3

Fe2O3(s) + 3CO(g) -> 2Fe(s) + 3CO2(g)

Enthalpy change for the above reaction is required.

Answer 4

hhahahahahahaha