Posted by HELP PLEASE on Thursday, February 16, 2012 at 1:47pm.
A) At 800 K the equilibrium constant for I2(g) <=> 2 I(g) is Kc = 3.1 105. If an equilibrium mixture in a 10.0L vessel contains 3.44*102 g of I(g), how many grams of I2 are in the mixture? answer is .060g
B)For 2 SO2(g) + O2(g)<=> 2 SO3(g), Kp = 3.0*104 at 700 K. In a 2.00L vessel the equilibrium mixture contains 1.03 g of SO3 and 0.170 g of O2. How many grams of SO2 are in the vessel?
I don't know how to do B

AP CHEMISTRY  DrBob222, Thursday, February 16, 2012 at 3:27pm
On #2:
Convert 1.03 g SO3 to moles, then to pressure using PV = nRT.
Do the same for 0.170g O2.
Substitute into Kp expression and solve for pSO2. Finally, use PV = nRT to solve for moles and convert to grams.