For the reaction 2HI(g) <----> H2(g) + I2(g),

Kc = 0.0198 at 721K. What is the HI concentration at 721K if [H2] = 0.120 M and [I2] = 0.0150 M?

I'm getting .303 M but that's not one of the options.

Annika, is it?

We have only a couple of chem tutors here and one is having internet troubles. Please be patient, and don't keep reposting the same question.

Thanks.