# Homework Help: Calculate degree of dissociation

1. Oct 30, 2012

### utkarshakash

1. The problem statement, all variables and given/known data
Vapour density of $N_2O_4$ which dissociated according to the equation
$N_2O_4(g) \Leftrightarrow 2NO_2(g)$ is 25.67 at 100°C and a pressure of 1 atm. Calculate the degree of dissociation and $K_p$ for the reaction

2. Relevant equations

3. The attempt at a solution
$\alpha = \frac{D_t-D_o}{D_o}$

$D_t = \frac{92}{2}$
Plugging in the values does not yield desired answer.

2. Oct 30, 2012

### Staff: Mentor

Please elaborate on what you are doing. What are Dt and D0? What is 92?

Is that the whole question? Either I am missing something or it can't be solved as given.

3. Oct 30, 2012

### Saitama

I suppose the OP directly posted the equations without showing how he/she has got it. If i remember correctly, Dt and Do are the theoretical and observed vapour density of a mixture at equilibrium. 92 is the molar mass of N2O4.

4. Oct 30, 2012

### utkarshakash

Yes thats right. But the answer which I'm getting is wrong.