avian777

10+ Year Member
Jul 11, 2008
39
0
Status
Pre-Dental
i thought this is an easy question:
what is the oxidation number of chromium in Na2Cr2O7
i thought it was +6, but the answer is +3, can anyone explain??
also,
heat + C(s) + CO2 <----> 2 CO(g)
If the pressure on the system is increased and the temperature kept constant, what will be the result?
the answer is : the amount of CO will decrease and that of C and CO2 will increase
I thought it will be the same for C(s) since this is in solid state and isn't considered in the equilibrium equation. I think this also relates to the concept between Keq and Ksp, in common ion effect and le chaterlier principle the equil still shift toward the solid state if there were common ion with the products eventhougth we do not include the concentration of the solid to be dissociated in the Ksp equation. Anyway, i'm very confused and hope someone can help me to clarify things up. Big thanks, dat tomorrow!!!! scared....
 
Jul 11, 2009
120
0
Status
Pre-Dental
The oxidation number would be +6...so the answer key must be wrong.
On the other question... the reason it would shift to the left is b/c a gas is made up of more particles and when pressure is increased the rxn will shift to the side with less perticles.