If a reaction vessel at that temperature initially contains 0.0400 M NO2 and 0.0400 M N2O4, what is the concentration of NO2 at equilibrium

0.088 M.

Explanation:

Assuming that the temperature is 429 K, we can calculate the concentration of NO₂. Kc(429K) = 0.490.

The reaction is:

N₂O₄(g)  ⇄  2NO₂(g)

0.04             0.04

0.04 - x          0.04 + 2x

The constant of the reaction is:

By solving the above equation for x we have:

x = 0.024 = [NO₂]      

Hence the concentration of NO₂ is:

I hope it helps you!

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.

it is the most commonly accepted one