Which pieces of chromatography equipment are involved in the mobile phase?

Idon’t understand this page, can someone ?

C3h8o3 - glycerol major species present when dissolved in water

Voltaic cells produce a positive overall charge. what does this indicate? a. the reaction is likely to be endothermic. b. the reaction is spontaneous. c. the reaction is not likely to occur. d. the reaction is not spontaneous.