At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.300 M and [NO]=0.500 M. N2(g)+O2(g)−⇀↽−2NO(g)If more NOis added, bringing its concentration to 0.800 M, what will the final concentration of NO be after equilibrium is re‑established?

[NO] = 0.636 M

Explanation:

The equation for the reaction = N₂(g) + O₂(g)  ⇄  2NO(g)

Given that [N₂]=[O₂]= 0.300 M and  [NO]=0.500 M

The equilibrium constant for the above equation can be written as:

(since there are 2 moles of NO and 1 mole of N₂ and O₂ in the equation above).

= 2.778

Furthermore, the question proceeds by stating that when more NO is added, there is increase in concentration, bringing it to 0.800 M.

Let construct an ICE table in order to determine the change in concentration

                               N₂(g)         +         O₂(g)           ⇄           2NO(g)

Initial (M)                 0.300                  0.300                         0.800

Change (M)              + x                      + x                               -2x

Equilibrium (M)        0.300+x             0.300+x                      0.800-2x

Again,    

Squaring both the Left-hand side(L.H.S) and the Right-hand side(R.H.S), we have:

1.667[0.300+x]  =  [0.800-2x]

0.5001 + 1.667x = 0.800 - 2x

0.5001 - 0.800 = -1.667x - 2x

- 0.2999 =  -3.667x

x =

x = 0.082

So, the final concentration of NO from the ICE table after the equilibrium has been re-established is;

[NO] = 0.800 - 2x

[NO] = 0.800 - 2(0.082)

[NO] = 0.636 M

Therefore, the final concentration of NO be after equilibrium is re‑established = 0.636 M

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.