Exothermic and endothermic reactions – Acid-base titration

CB-IN-39/EV: This kit enables to test the energy side of the different chemical processes that can absorb or release heat. They are classified into: exothermic reactions, when they release heat to the environment; endothermic reactions, when they absorb heat from the environment; athermic reactions, when there is no heat exchange. Furthermore this kit enables to understand the concept of spontaneousness in natural phenomena. Spontaneous phenomena arise without the intervention of external forces or agents and they cannot recover their original state autonomously. The energy released during the reaction consists of two factors: one is the heat exchanged during the reactions, and the other depends on the organization of particles (probabilistic ordering or factor). The sum of favourable and unfavourable effects due to these two factors determines whether a reaction is spontaneous or non spontaneous. CB-IN 40/EV: This kit enables to carry out an acid-base titration which can determine the titer, that is the concentration of a solution of an acid (or of a base) by measuring the volume of a base (or of an acid) of known concentration; then this base (or acid) will react completely with a known volume of the solution having to be titrated. The achievement of stoichiometric equivalence is signalled by the colour change of a proper indicator. For educational reasons it is better to treat solutions whose concentration are not too different, so that calculations may be easier. Therefore the exercise proposed by this kit will use an acid whose concentration is approximately half the titrating base.