posted by bob .
hydgogen and iodine form HI(g)per the reaction H2(g)+I2=2HI(g). If 2 L of iodine gas at .5 atm and 295 K react with excess oxygen, how many liters of HI at 295K and 1 atm will form?
If you mean excess hydrogen, then 2 L of iodine gas will form 4 liters of HI gas at the same temp, pressure, according to the balanced equation. However, pressure is doubled, so it will form only 2 liters.