Answer:
Electron loss is always associated with an increase in oxidation number- True
An exothermic reaction occurs when the energy required to break bonds in reactants is less than the energy released by bond formation in the products. True
The concentrations of pure liquids and pure solids are never included in an equilibrium constant expression because such concentrations never change. True
Step-by-step explanation:
Oxidation implies loss of electrons. When a specie looses electrons, its oxidation number increases. For instance; Fe(s) -----> Fe^2+(aq) + 2e implies an increase in oxidation number of Fe from 0 to +2.
In an exothermic reaction, the energy required to break the bonds in the reactants is less than the energy released when new bonds form in the products.
We do not include the concentrations of pure liquids and pure solids in the equilibrium constant expression because the concentration of these do not change significantly throughout the reaction.