Question

Find the value of delta H net for the following equation:

SnBr2(s) + TiCl4(l) -> TiBr2(s) + SnCl4(l)

Use the following reactions to help solve for the net value:

1) SnCl2(s) + TiBr2(s) -> SnBr2(s) + Ticl2(s) Delta H=+4.2

2) SnCl2(s) + Cl2(g) -> TiCl4(l) deltaH=-195

3) TiCl2(s) + Cl2(g) ->TiCl4(l) deltaH=-273

SnCl2(s) + Cl2(g) -> SnCl4(l) deltaH=-195

TiCl4(l) -> TiCl2(s) + Cl2(g) deltaH=+273

SnCl2(s) + TiCl4(l) -> TiCl2(s) + SnCl4(l) deltaH net = +78kJ

Everything that I have posted is exactly what was stated in the problem so I guess everything is in kJ.

Answer 1

You have an error on the product side of the third reaction. The reaction produces SnCl4.
I was wondering what was wrong Haha.
Anyway...
Hess's Law...Oh Joy!
If we look at the given reactions we see that we must flip three of the reactions to produce the overall reaction that you stated above. So you just fiddle around with it to cancel out compounds. And you end up flipping the first, third, and sixth reaction. You change the delta H value to the opposite sign and add all the enthalphys. So you get.... +73.8 Kj for your answer!

Answer 2

I mean an error on the second reaction.