Mg(s) + 2H2O(l) ---> Mg^2+(aq) + 2OH-(aq) + H2(g) Use the net ionic equation for
ID: 500983 • Letter: M
Question
Mg(s) + 2H2O(l) ---> Mg^2+(aq) + 2OH-(aq) + H2(g) Use the net ionic equation for the reaction above and look up the standard enthalpies of formation values for the products and reactants and calculate the delta H. Mg(s) + 2H2O(l) ---> Mg^2+(aq) + 2OH-(aq) + H2(g) Use the net ionic equation for the reaction above and look up the standard enthalpies of formation values for the products and reactants and calculate the delta H. Use the net ionic equation for the reaction above and look up the standard enthalpies of formation values for the products and reactants and calculate the delta H.Explanation / Answer
Actually..I couldnt get the values of standard enthalpies of formation...but I will give another method...
Mg(s) + 2H2O(l) ---> Mg^2+(aq) + 2OH-(aq) + H2(g)
Ef = -2.38V Er = -0.42
Ecell = + 1.96 V
G o = -nFEo
G = Gibb’s free energy.
n = number of moles of electrons.
F = Faraday constant 9.6485309 x 104 J/V
mol -E o implies nonspontaneous.
+Eo implies spontaneous (would be a good battery!)
DG = DH - TS
DH = DG + TS