2.1 chemical systems

define a system

a chemical reaction

define surroundings

everything else around the chemical reaction

define an open system

matter AND energy can be exchanged between the system and its surroundings

define a closed system

only energy is exchanged between the system and its surroundings

define an irreversible reaction

reaction where the reactants form products, unidirectionalefd

define a reversible reaction

when reactants form products, the products can react again to reform the reactants

what occurs to a reversible reaction in a closed system

the reaction will eventually reach a point where the rates of forward and reverse reactions are equal. at this point, no further change will appear to the observer. this system has reached a state of equilibrium

why does a system reach equilibrium

the forward and reverse reactions compete with one another, preventing either reaction from going to completion. both reactions occur at the same rate, products are forming reactants at the same rate they are being formed

what occurs to a reversible reaction in an open system

rate of either reaction is not equal, equilibrium cannot be reached in an open system because energy and matter can leave the system.

describe the activation energy level for a non reversible reaction

typically high activation energy

describe the activation energy level for a reversible reaction

typically low activation energy