An industrial chemist carries out some research into the NO/O2/NO2 equilibrium used in Stage 2 of the manufacture of nitric acid.
• The chemist mixes together 0.80mol NO(g) and 0.70 mol of O2(g) in a container with a volume of 2.0dm3.
• The chemist heats the mixture and allows it to stand at constant temperature to reach equilibrium.
The container is kept under pressure so that the total volume is maintained at 2.0 dm3.
• At equilibrium, 75% of the NO has reacted.
The question is to work out the KC value.. I'm really stuck
I got the moles at equilibrium of NO2 as 0.60… meaning a 0.20 difference. But when you take 0.20 from 0.70 you get 0.50, but the mark scheme is stating the moles of 02 at equilibrium are 0.40. I'm probably doing this wrong, or being really stupid but any help would really be appreciated