[Spoogle]

Hi there,

Could somebody have a look at this as it's irritating me being unable to see if I'm doing something wrong or if there's an error in the question.

"9. Nitrogen dioxide dissociates according to the following equation.

2NO2(g) <--> 2NO(g) + O2(g)

When 46.0 g of nitrogen dioxide were heated to a constant temperature, T, in a flask of volume 11.5 dm3, an equilibrium mixture was formed which contained 16.0 g of oxygen."

I'm getting an error when doing this as 16g/32RMM for oxygen gives 0.5 mole.
We start with 46g/46RMM NO2 which is 1 mole.
Thus using 2:1 ratio at equilibrium we finish with 0 moles NO2 and so you cannot work out a value for Kc
Even converting your mole values into mol dm-3 by dividing by 11.5 first makes no difference.

Is it me or the question ? :\

Thanks for the help

[DevaDevil]

you are correct, 1 mole NO2 gives 0.5 mole of oxygen in a full reaction. this is then not an equilibrium.

[Spoogle]

Thank you, was driving me mad when I thought I had these fully cracked.