Directions: each set of lettered choices below refers to the numbered words or statements immediately following it. select the one lettered choice that best fits each word or statement. a choice may be used once, more than once, or not at all in each set. the figure below represents a food web in a particular ecosystem. each letter represents a species. the arrows indicate the direction of energy flow.
the gases are contained in a reaction vessel and are in equilibrium at 298 k
(a) activation energy
(b) total mass of the system
(c) molar concentration of xz4g)
(d) number of molecules present (e) equilibrium constant
1. is decreased by the addition of a catalyst
2. is decreased when the volume of the reaction vessel is increased and equilibrium is reestablished at 298 k