posted by Alex on .
I need help I can't seem to get the right answer. Please help!
1/2 H_2 (g) + 1/2 Cl_2 (g) --> HCl (g) -92.3 kJ/mol
Na(s) + 1/2 O_2(g) + 1/2H_2(g) --> NaOH(s) -426.8 kJ/mol
NaCl(s) --> Na(s) + 1/2Cl_2(g) 411.1 kJ/mol
H_2O(l) -->H_2(g) + 1/2O_2(g) 285.8 kJ/mol
HCl(g) --> HCl(aq) -75.2 kJ/mol
NaOH(s) --> NaOH(aq) -41.8 kJ/mol
HCl (aq) + NaOH (aq) --> NaCl (aq) + H_2O (l) -56 kJ/mol
I need the dH for H for NaCl(s) NaCl(aq) kJ/mol
I keep getting -411.1 kJ /mol but it says it's wrong what am I doing wrong?
Count the equations from the top.
I put all of these together and came up with the final equation you want.
Add eqn 2,6,7.1.5,4 and 3. I added all of the kJ/mol values for dH and came up with 4.8 but it's so hard to see on my computer I could have missed something. You should confirm that and watch the number of significant figures.