Final answer:
Chemical reactions can involve heat release, as seen in the reaction between NaOH and HCl forming NaCl and H2O, with a resultant temperature increase. Calorimetry allows for the measurement of this enthalpy change. In a titration, the amount of one reactant can be quantified by the known concentration and volume of the other.
Step-by-step explanation:
Chemical reactions often involve changes in temperature due to the absorption or release of heat. This thermal exchange is quantified as the reaction's enthalpy change. For instance, when an aqueous solution of sodium hydroxide (NaOH) reacts with hydrochloric acid (HCl), sodium chloride (NaCl) and water (H₂O) are formed, and heat is released in the process. Using calorimetry, we can measure this temperature change and calculate the enthalpy change.
In a typical experiment, dissolving 4.0 g (or 0.10 mol) of NaOH and 3.65 g (or 0.10 mol) of HCl each in 100.0 mL of water and mixing them in a calorimeter will result in a temperature rise. The relevant chemical equation is: NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l). Assuming the heat capacities and densities of the solutions are similar to water, the heat change (q) can be calculated using the specific heat capacity of water and the mass of the resultant solution.
In a titration scenario, knowing the volume and molarity of one reactant can help determine the number of moles of the other reactant used, allowing for further stoichiometric calculations.