1. which processes are taking place in the system represented by the following equation?
2co(g) + o2(g) →← 2co2(g)

2. consider the reaction represented by the equation 2hi(g) →← h2(g) + i2(g). at a temperature of 520 °c, the equilibrium concentration of hi is 0.80 m, of h2 is 0.010 m, and of i2 is 0.010 m. what is the k for the reaction?

For the first question:
The double directional arrow (→←) shows that the equation is moving at both directions (forward and reverse) simultaneously (at the same time).
So for the equation, two processes are happening at the same time:
1- Carbon monoxide combines with oxygen to form carbon dioxide
     2CO2 + O2 ..........> 2CO2
2- Carbon dioxide dissociates to give carbon monoxide and oxygen
     2CO + O2 <........ 2CO2

For the second question:
The equilibrium constant can be calculated as shown in the attached picture.
Applying this rule to the given equation, we find that:
k= [(0.01^1)(0.01^1)] / [(0.8^2)] = 1.5625 x 10^-4