extent of chemical reactions AOS2 Flashcards
what is a system in terms of thermochemical reactions?
in an endothermic reaction, the system absorbs energy from the surroundings whereas in an exothermic reaction, energy is released to the surroundings by the system
what is an open system?
in which matter and energy can be exchanged with the surroundings and the most common situation in everyday life is an open system
what is a closed system?
in which only energy is exchanged with the surroundings
how to show in a chemical equation that a reaction is reversible as opposed to irreversible?
a double arrow
how do reversible reactions work?
the formation of products as a result of collisions between reactant particles isn’t the end of the process. once some products are formed, collisions between product particles can result in the reactants being re-formed
what is the link between reversible reactions and equilibrium?
reversible reactions can reach a state of equilibrium where the overall concentrations of reactants and products do not change over time. equilibrium occurs because reversible reactions in a closed system eventually reach a situation where the rate of the forward reaction and the rate of the reverse reaction are equal. note that at equilibrium there may still be significant amounts of reactants in the system
how are some chemical reactions reversible?
when particles collide, the energy associated with collisions can break bonds in the reacting particles, allowing them to rearrange to form products. once the products form, it is possible for the reverse process to occur because if the newly formed product particles collide with enough energy to break their bonds then it’s possible to re-form the original reactants
