Large concentrations of hydrogen ion and hydroxide ion cannot coexist in solution, because the neutralization reaction
strongly favors the product (water).
In this experiment, an aqueous hydrochloric acid solution will be added to an aqueous sodium hydroxide solution. The neutralization reaction will occur until either H+ or OH- is entirely consumed. The reactant which is consumed first is called the limiting reactant.
The molar enthalpy of neutralization is defined as
ΔHneut = | qneut n |
where qneut is the heat of neutralization, measured calorimetrically, and n is the moles of the limiting reactant.
Objective:
Approach:
Part 1In this part of the experiment, the calorimeter is filled with 50.0 mL of 1.00 M aqueous NaOH. The heat capacity of the calorimeter (Ccal) is 78.2 J oC-1. The specific heat capacity of the aqueous solutions is 4.184 J oC-1 g-1. |
Part 2The conditions in this part of the experiment are the same as those in Part 1. The heat capacity of the calorimeter (Ccal) is 78.2 J oC-1. The specific heat capacity of the aqueous solutions is 4.184 J oC-1 g-1. Repeat the experiment using various volumes of HCl and NaOH. You should get the same molar enthalpy of neutralization. |