0 votes
3 views
ago in Chemical equilibrium by (450 points)
Consider the reaction: 2NOBr(g) <=> 2NO(g) + Br2(g), which has an equilibrium constant of 1.5 x 10^-5 at a certain temperature. If you start with 0.10 M of NOBr and let the reaction reach equilibrium, find the equilibrium concentrations of NOBr, NO, and Br2.

1 Answer

0 votes
ago by (430 points)
To find the equilibrium concentrations of NOBr, NO, and Br2, we can set up an ICE  Initial, Change, Equilibrium  table:``          2NOBr g  <=> 2NO g  + Br2 g Initial:    0.10 M      0 M        0 MChange:    -2x M       +2x M      +x MEquilibrium:0.10-2x M   2x M       x M``The equilibrium constant expression for this reaction is:Kc = [NO]^2[Br2] / [NOBr]^2We can plug in the equilibrium concentrations into the expression:1.5 x 10^-5 =  2x ^2 x  /  0.10 - 2x ^2Now we need to solve for x: 1.5 x 10^-5  0.10 - 2x ^2 =  2x ^2 x It's a cubic equation, which can be difficult to solve directly. However, since Kc is very small, we can assume that x is also very small, and therefore 2x is also very small compared to 0.10. So, we can approximate: 1.5 x 10^-5  0.10 ^2 =  2x ^2 x Now we can solve for x: 1.5 x 10^-5  0.01  = 4x^31.5 x 10^-7 = 4x^3x^3 =  1.5 x 10^-7  / 4x^3  3.75 x 10^-8x  3.36 x 10^-3Now we can find the equilibrium concentrations:[NOBr] = 0.10 - 2x  0.10 - 2 3.36 x 10^-3   0.0933 M[NO] = 2x  2 3.36 x 10^-3   6.72 x 10^-3 M[Br2] = x  3.36 x 10^-3 MSo, the equilibrium concentrations are approximately [NOBr] = 0.0933 M, [NO] = 6.72 x 10^-3 M, and [Br2] = 3.36 x 10^-3 M.

Related questions

Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...