Question

At 1285 degree C the equilibrium constant for the reactin Br2(g) <> 2Br(g) is Keq= 1.04 * 10^-3. A 0.200 L vessel containing an equilibrium mixture of the gases has 0.245 Br2(g) in it. What is the mass of Br(g) in the vessel?

Please help, Thanks!!

Answer 1

At 1285 degree C the equilibrium constant for the reactin Br2(g) <> 2Br(g) is Keq= 1.04 * 10^-3. A 0.200 L vessel containing an equilibrium mixture of the gases has 0.245 <b>WHAT</b> Br2(g) in it. What is the mass of Br(g) in the vessel?

<b>No unit is listed. That could be moles, molarity, g/L, just what.</b>

Answer 2

I am sorry it is in grams.

Answer 3

Br2(g) <> 2Br(g)

(Br2) = moles/L =
moles = g/molar mass = 0.245 g/159.81 = 0.00153 and the volume is 0.2 L; therefore,
(Br2) = 0.00153/0.200 = 0.00766 at equilibrium.
Substitute into Keq expression and solve for (Br) and that will be in moles/L. Multiply that by 0.200 L to convert to moles and by atomic mass Br to convert to grams (although g Br doesn't make sense to me since Br doesn't exist as monatomic gas (I guess it might at umpteen thousand degrees K0.