Measurement of the Heat of Neutralization of an Acid

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Measurement of the Heat of Neutralization of an Acid

CHM 152INCRN:February 5, 2000

I. Purpose of Experiment

The purpose of this lab is to measure the heat released in the reaction of an acid and a base. This will demonstrate an enthalpy reaction, showing energy being released.

II. Chemicals and Equipment

The following chemicals and equipment will be utilized for the experiment:

|Chemicals |Equipment | |2.0 M HCl |LabPro unit with temperature probe | |2.0 M NaOH |2 Styrofoam cups | |H2O (Distilled) |Ring stand with clamps | | |Graduated cylinder | | |150 ml beaker | | |Heating Plate | | |Magnetic stir | | |Stir plate |

III. Experimental Procedure

Begin our experiment by setting up the apparatus below; there are two Styrofoam cups (one inside another) and a thermometer clamp to hold the probe. Create a lid for the calorimeter using an inverted cup, cut in half and placing the cups on a stirring plate. Next, pour 25 ml of distilled water into the calorimeter, and take an initial temperature reading (assume that 1 g/ml so the weight of the water is 25 g). Pour another 25 ml of distilled water into a 150 ml beaker and heat on a hot plate until boiling, taking an initial reading after it boils. Set up a Vernier LabPro, recording a data point every ten seconds for five minutes, placing the probe in the calorimeter. Then, quickly add the hot water to the cool water, using a magnetic stir, we stir the mixture so the temperature will equilibrate. When finished with the experiment transfer the temperature vs. time plot to a computer, repeat this procedure for a total of three trials.

Developing a procedure similar to that above, using an acid and a base with the following equation.

HCl (aq) + NaOH (aq) →NaCl (aq) + H2O (l)

The previous procedure as an outline, use the same apparatus and Styrofoam cups. Create a lid for the calorimeter using an inverted cup, cut in half. Next, pour 25 ml of NaOH into the calorimeter, and get an initial temperature reading for the sodium hydroxide (assume that 1 g/ml so the weight of the water is 25 g). Here our procedure will differ, we varied our amounts of HCl as 10, 15 and 20 ml increments (One for each of our trials). Then pour 10 ml of HCl into a 150 ml beaker for our first acid-base trial, taking an initial temperature reading from the acid as well before mixing. Set up a Vernier LabPro, recording a data point every ten seconds for five minutes, placing the probe in the calorimeter then quickly add the HCl to the NaCl, using a magnetic stir to stir the mixture so the temperature will equilibrate. When finished with the experiment transfer the temperature vs. time plot to a computer, repeat this procedure for a total of three trials. Remember to change the amounts of HCl in each trial as noted, utilizing the HCl as our limiting reactant.

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IV. Data Tables

As our experiment began, we start...
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