1. D ETERMINATION OF ENTHALPIES OF NEUTRALIZATION  Reaction of neutralization of strong acid by a strong base Place in the calorimeter 40 mL of 2M sodium hydroxide at room temperature. Prepare a glass at the same temperature with 40 mL of a 2M hydrochloric acid solution. Add it to the calorimeter and record the temperature as precisely as possible in terms of time.

2.  Reaction of neutralization of a weak acid by strong base. Repeat the process of the previous section using 40 mL of 2M sodium hydroxide and 40 mL of a 2M solution of acetic acid. Calculate the enthalpy of neutralization.

3. Calculations and graphs 1.- Calculate the enthalpy of neutralization for each neutralization reaction study and compare the results. 2.- Add the graphs for the four experiments (on graph paper), indicating the value of Tm for each one of them

4. D ETERMINATION OF ENTHALPIES OF REACTION AND APPLICATION OF H ESS ' S LAW  Determination of the enthalpy of reaction of hydrochloric acid with ammonia Measure 1 50 mL of HCl (aq) 2 M, record the temperature of the solution and, if it remains stable, put in the calorimeter. Measure 50 mL of NH 3 (aq) 2 M using a clean dry test tube and record the temperature of the dissolution profile stable.

5. Add NH 3 (ac) to the calorimeter and record the temperature at intervals of 1 minute, for five minutes, while stirring the calorimeter. Plot the relation temperature / time received. Calculate, by extrapolation, the temperature Tm. Calculate the value of DH for: NH 3 (aq) + HCl (aq) → NH 4 + (aq) + Cl-(aq)

6.  Determination of the enthalpy of solution of ammonium chloride Weigh between 10 and 11 grams of solid NH 4 Cl. Measure 50 mL of distilled water, record the temperature remains stable when put in the calorimeter. Add solid NH 4 Cl to the calorimeter and record the temperature at intervals of 1 minute while stirring the calorimeter. Plot the relation temperature / time received. Calculate, by extrapolation, the temperature Tm. Calculate the value of DH for: NH 4 Cl (s) → NH 4 + (aq) + Cl-(aq)