Calculate the value of the standard enthalpy change for each of the following reactions (standard enthalpy for Na2SO4(s) is -1375.653 kj/mole):
a)4HBr(g) + O2(g) = 2H2O(I) + 2Br(I)
b)2Na(OH)(s) + SO3(g) = Na2SO4(s) + H2O(g)
c)CH4(g) + 4CI2(g) = CCI4(I) + 4HCI(g)
d)Fe2O3(s) + 6HCI(g) = 2FeCI3(s) + 2H2O(g)
See your earlier post. I'll explain something here if you don't understand it but I'm not about to rework four problems just for the fun of it.
To calculate the standard enthalpy change for each of the reactions, you will need to use the known standard enthalpy values for the reactants and products.
a) 4HBr(g) + O2(g) = 2H2O(I) + 2Br(I)
The enthalpy change for this reaction can be calculated by subtracting the sum of the enthalpy of the reactants from the sum of the enthalpy of the products.
Enthalpy change = [2 × enthalpy of H2O(I)] + [2 × enthalpy of Br(I)] - [4 × enthalpy of HBr(g)] - [enthalpy of O2(g)]
b) 2Na(OH)(s) + SO3(g) = Na2SO4(s) + H2O(g)
Similarly, the enthalpy change for this reaction can be calculated by subtracting the sum of the enthalpy of the reactants from the sum of the enthalpy of the products.
Enthalpy change = [enthalpy of Na2SO4(s)] + [enthalpy of H2O(g)] - [2 × enthalpy of Na(OH)(s)] - [enthalpy of SO3(g)]
c) CH4(g) + 4CI2(g) = CCI4(I) + 4HCI(g)
To calculate the enthalpy change for this reaction, subtract the sum of the enthalpy of the reactants from the sum of the enthalpy of the products.
Enthalpy change = [enthalpy of CCI4(I)] + [4 × enthalpy of HCI(g)] - [enthalpy of CH4(g)] - [4 × enthalpy of CI2(g)]
d) Fe2O3(s) + 6HCI(g) = 2FeCI3(s) + 2H2O(g)
Again, calculate the enthalpy change by subtracting the sum of the enthalpy of the reactants from the sum of the enthalpy of the products.
Enthalpy change = [2 × enthalpy of FeCI3(s)] + [2 × enthalpy of H2O(g)] - [enthalpy of Fe2O3(s)] - [6 × enthalpy of HCI(g)]
You will need to look up the standard enthalpy values for H2O(I), Br(I), Na(OH)(s), SO3(g), HCI(g), CH4(g), CI2(g), FeCI3(s), and Fe2O3(s) to substitute into the equations.