Given ∆H° for the following reactions:H2(g)+O2(g)➡️2H2O(l):Cu(s)+1/2 O2(g)➡️CuO(s)_What further data is needed, if any,for calculation of ∆H° for the following reactions? CuO(s)+H2(g)➡️Cu(s)+H20(g)

1 Answer
Mar 27, 2018

It is needed to eliminate liquid water by adding an electrolysis reaction and a gas water formation equations to the previous equation

Explanation:

German Henri Hess, in 1840, principle states:
The enthalpy of a given chemical reaction is constant, regardless of the reaction happening in one step or many steps. So, it is possible to get a reactional enthalpy from several reactions.

Flip 2nd reaction and adding both:
CuO(s) -----> Cu(s) + 0.5O_2(g)
H_2(g) + O_2(g)
-----> 2H_2 O(g)

=>

CuO(s) + O_2(g)__-----> Cu(s) + 2H_2 O(L) + 0.5O_2(g)

It is needed to eliminate liquid water by adding an electrolysis reaction and a gas water formation equations to the previous equation

2H_2 O (L) ----> 2H_2 (g) + 2O (g)
H_2 (g) + O (g)
----> H_2 O (g)

=>Finally,
CuO(s) + H_2(g)__-----> Cu(s) + H_2 O(g)