Static and Dynamic Equilibrium – Practice


1) Would the following systems be considered open or closed?

a) an acid and a base reacting in an open beaker

b) a standardised solution in a volumetric flask with a stopper on top

c) combustion of fuel

d) coffee in a cup with a sugar cube dissolving and the lid is on.

2) In a closed system, COCl2 decomposes to form CO and Cl2. Draw a diagram to represent this system at dynamic equilibrium:

3) An equilibrium reaction is established when nitrogen and hydrogen are mixed in a container to produce ammonia gas.

a) Write a balanced chemical equation for this reaction

b) Sketch a concentration-time graph which illustrates this system reaching equilibrium. Assume there was no ammonia present in the container initially:

Quick Answers:

1) a) open    b) closed    c) open    d) closed (assume no hole in lid)


3) a) 3H2(g) + N2(g) ⇔ 2NH3(g)


Worked Answers: (coming soon)