[katyi6]

Okay so the question states: At 1000 K gas phase molecular Iodine (I2) is in equilibrium with atoms ( I atomic mass 126.9 g/mol)
I2 --- 2I   Kc= 3.8 x 10 ^ -5.

A 5.79 g sample of molecular iodine is sealed in a 2.30 L flask and heated to 1000 K. What are the equilibrium concentrations of molecular iodine and iodide atoms?

So I found the moles of iodine which came out to be .0456 moles
then I made an ICE table which basically came out to me having

3.8 x 10 ^-5 = 4x^2 / 2.30 (0.0456 -x ) and now im stuck.

the answers are supposed to be = 6.1 x 10 ^ -4 and [I2] = 9.6 x 10 ^ -3

Thank you in advance for the help

[rabolisk]

Your calculations aren't working out because you messed up earlier. 0.0456 mol is not correct. Your methods are correct, though.

[katyi6]

ohhhhh wait, are the moles supposed to be 0.0228?
i did not multiply molar mass by 2!