Technically, one needs a volume since M is substituted into the Kc expression and not mols. You don't have a volume listed. However, the volume cancels as follows:
Kc = (mols HI/v)^2/(mols H2/v)(mols I2/v). That means we can assume any volume or ignore volume (or use 1 L)
(H2) initial = 0.2
(I2) initial = 0.15
(HI) equilibrium = 0.26
........H2 + I2 ==> 2HI
I......0.2..0.15......0
C......-x....-x......2x
E...0.2-x...0.15-x...2x
but you know 2x = 0.26 and that allows you to evaluate mols H2 and mols I2.
Substitute the E line into Kc expression and solve for Kc.
Post your work if you get stuck.
When 0.20 mol of hydrogen gas and 0.15 mol of iodine gas are heated at 723 K until equilibrium is established, the equilibrium mixture is found to contain 0.26 mol of hydrogen iodide.
The equation for the reaction is as follows.
H2(g) + I2(g) ↔ 2HI(g)
What is the equilibrium constant Kc of this reaction? Show the way with initial, react, and equilibrium mol.
1 answer