chemistry
posted by jessie on .
Nitrosyl bromide decomposes according to the following equation.
2NOBr (g)(equilibrium arrow) 2NO (g) + Br2 (g)
A sample of NOBr (0.64 mol) was placed in a 1.00L flask containing no NO or Br2. At equilibrium
the flask contained 0.46 mol of NOBr. How many moles of NO and Br2, respectively, are in the
flask at equilibrium?
A) 0.18, 0.18 B) 0.18, 0.090 C) 0.46, 0.46 D) 0.46, 0.23 E) 0.18, 0.360
i thought it was .18 .18 but i was wrong. how is this problem solved/

It's 0.18 and 0.09
..........2NOBr ==> 2NO + Br2
initial....0.64..... 0.....0
change.....2x.......+2x...+x
equilibrium. 0.46
0.640.46 = 0.18 and that is the same as NO (because the coefficients are equal) but the Br2 is 1/2 that. Or to say it another way.
2x = 0.640.46 = 0.18
x = 0.09
then 2NO = 2x = 0.18
x = Br2 = 0.09