Question

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?

Answer 1

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