A student places 2.00 mol of Br2(g) in a 2.00L reaction flask and allows the gas to decompose to Br(g).

Question

A student places 2.00 mol of Br2(g) in a 2.00L reaction flask and allows the gas to decompose to Br(g).

At equilibrium, 0.064 mol of Br(g) is present in the flask. Calculate the equilibrium concentration of Br2(g).

a)1.94 mol

b)0.64 mol

c)0.064 mol

d)none of these

e)0.80 mol

Answer 1

Br₂ <--> 2Br^-

2.............0......Initial...

-x........+2x......Change

2-x.......0.064..Equilibrium

Since 2x = 0.064, moles Br₂ @ equilibrium = 2.00 mol - 0.064 mol = 1.94 mol Br₂ in 2.0 L

[Br₂] = 0.968 M (answer d, none of these)