Thermodynamics, Enthalpy of Reaction Lab Essay

744 Words May 21st, 2014 3 Pages
Name
Lab Partner Name(s)
Thermodynamics, Enthalpy of Reaction Lab
March 27, 2014

I. Purpose

The purpose of this lab is to learn how to determine the heat of reaction.

II. Safety

1. Wear appropriate safety attire (goggles, aprons, hair tie, etc.).
2. Do not directly inhale or ingest chemicals.
3. Understand safety information regarding the chemicals being handled during the lab (hydrochloric acid, sodium hydroxide).
4. Be aware of how to operate all lab equipment.
5. Clean hands and experimentation area before exiting the lab.
6. Listen for any additional direction from the instructor.

III. Pre-lab Questions

1. Define ΔHrxn. ΔHrxn is enthalpy of products – reactants. (ΔHrxn = Hprod-Hreact).
2. In today’s lab
…show more content…
In the data table, record the temperature in ten second increments for a total of a minute and a half.

V. Data and Observations

NaOH(aq)+HCl(aq)→NaCl(aq)+H2O(l) Temperature (ºC) of HCl = 22.4 Temperature (ºC) of NaOH = 23.0 Initial Temperature (ºC) = 22.7
Time (sec)
Temperature (ºC)
Time (sec)
Temperature (ºC)
0
Cannot measure
50
36.7
10
36.6
60
36.6
20
36.7
70
36.5
30
36.8
80
36.5
40
36.8
90
36.5

VI. Calculations

VII. Conclusion

The purpose of this law was to learn how to determine the heat of reaction. A variety of topics were covered during this experiment including enthalpy of reaction, heat of formation, Hess’s Law, and calorimetry. The first being enthalpy of reaction, ΔHrxn, which is the heat or enthalpy change for a chemical reaction. The energy change is equal to the amount of heat transferred at a constant pressure in the reaction. The change represents the difference in enthalpy of the products and the reactants. The second, is the heat of formation (ΔH°f), which is also known as standard enthalpy of formation, and is defined as the change in enthalpy that accompanies the formation of one mole of a compound from its elements with all substances in their standard states. The enthalpy change for a given reaction can be calculated by subtracting the enthalpies of formation of the reactants from the enthalpies of formation of the products. During this experiment,

Related Documents