For the table with concentration changes, was it the Iodine that had its concentration increased?
If so, I put HI to increase and hydrogen to decrease, and Iodine to have increased, in order to keep the value of Kc constant.
If you think about it, Kc is constant, increasing Iodine increase the bottom of the fraction, so the value of the Kc expression decreases. We need to increase it again, so we need to increase the top and decrease the bottom, so HI rises, Hydrogen decreases, and Iodine decreases relative to its inital concentration (but relative to the previous experiment it has still increased).
Anyone agree (if it was hydrogen that had its concentration increased, my answer is the same but swap hydrogen and Iodine around)?