You have to convert the mass from g to kg since the unites for a joule is kgm²/s². When you do this you should have E=(1.0×10⁻⁷ kg)×(3.00×10⁸ m/s)². With that E=9.00×10⁹J which equals 9.00×10⁶kJ.
I hope this helps. Let me know if anything is unclear.
Answer : The equilibrium concentration of
is, 1.0 M
Explanation : Given,
Equilibrium concentration of
= 0.26 M
Volume of solution = 1.00 L
Equilibrium constant
= 4.0
The balanced equilibrium reaction will be,
![PCl_5\rightleftharpoons PCl_3+Cl_2](https://tex.z-dn.net/?f=PCl_5%5Crightleftharpoons%20PCl_3%2BCl_2)
The expression of equilibrium constant for the reaction will be:
![K_c=\frac{[PCl_3][Cl_2]}{[PCl_5]}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5BPCl_3%5D%5BCl_2%5D%7D%7B%5BPCl_5%5D%7D)
From the reaction we conclude that the concentration of
and
are equal.
Let the concentration of
be 'X'.
So, concentration of
= X
Now put all the values in this expression, we get :
![4.0=\frac{(X)\times (X)}{0.26}](https://tex.z-dn.net/?f=4.0%3D%5Cfrac%7B%28X%29%5Ctimes%20%28X%29%7D%7B0.26%7D)
![4.0=\frac{(X)^2}{0.26}](https://tex.z-dn.net/?f=4.0%3D%5Cfrac%7B%28X%29%5E2%7D%7B0.26%7D)
![X=1.0M](https://tex.z-dn.net/?f=X%3D1.0M)
Thus,
The concentration of
at equilibrium = X = 1.0 M
The concentration of
at equilibrium = X = 1.0 M