Hello there, I am unsure about the following question and would like some help to understand please! Consider the following systems: a) a container that is half filled with alcohol, stoppered and allowed to stand for several days b) crystals of KMnO4 that are dissolved in water until the water becomes a uniform purple colour and a constant amount of crystal remainds in the container c) an ice cube in a beaker of water in a normal classroom d) moth balls that are placed in an empty flash that is then stoppered and alllowed to stand for several days Which of the above are in an equilibrium state? i) a and b ii) a,b,d iii) b,c iv) a,b,c,d At this moment, I am picking IV because A and D are stoppered in the flask so it would eventually reach equilibrium since no vapour is allowed to escape. As for B, when the crystals mix in with water it causes stress to the equilibrium but then it would eventually fix itself back to equilibrium and c is because ice cube is water so it will melt into water, which causes no change to the equilibrium. Thank you!