Question

Explain, in terms of particles, concentration, and reaction rate, what you expect to happen when methane gas (CH4) and hydrogen sulfide gas (H2S) are sealed in a flask and reach a state of equilibrium.

CH4 (g) +2 H2S (g) Two arrows stacked on top of each other. The top arrow points to the right. The bottom arrow points to the left. CS2 (g) + 4 H2 (g)

Answer 1

Step-by-step explanation:

The equation of this equilibrium reaction is shown below:

CH₄ + 2H₂S ⇄ CS₂ + 4H₂

All the gases in this reaction are in a gaseous phase.

When gases are in equilibrium with one another, we can make some comments about their particles, concentration and reaction rate.

For the particles:

The magnitude of the kinetic energy here is very great according to the kinetic theory of matter. This is because the particles are in a uniform gaseous phase.

In terms of concentration

When dealing with gases in equilibrium, we talk more of the concentration with regards to pressure. Pressure is equivalent to concentration when we consider gaseous reactions. An increase in pressrue is like applying a stress to the system. Based on Le Chatelier's principle, increase in pressure favors the side with smaller volume:

CH₄ + 2H₂S ⇄ CS₂ + 4H₂

3 moles of gases 5 moles of gases

Increase in pressure will favor the reactant side.

Reaction rate

The rate at which this reaction will proceed would be very fast. This is because gases have the fastest rate of reaction. The equilibrium will quickly be reached.