# 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
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

• ###### Chemistry: Magnesium Experiment Essay

first reaction, the final temperature of the reaction rose to only about 65C due to the fan and air conditioning in the area that we were working in. We consulted with the instructor, and he told us that the final temperature had to be at least 70C. We moved to another area where the fan was not blowing directly at us, and we did the first reaction again, finally obtaining the desired temperature. The next problems we encountered were in the calculations of the enthalpy for the reaction:…

Words: 625 - Pages: 3
• ###### Essay Enthalpy Of Formation Of Acid

The goal of this lab was to determine the enthalpy of formation of salicylic acid. Enthalpy of formation is the change of enthalpy, also known as the change of energy, when one mole of a substance is combusted in its standard state. A mole is a standard unit used to quantify how much of a substance you have. Similar to how a dollar is a unit for money in the United States, a mole is a quantitative unit of a substance in chemistry. This experiment was performed by assembling a bomb in class! First…

Words: 777 - Pages: 4
• ###### Essay Enthalpy And Enthalpy Of A Calorimeter

Almost all chemical reactions involve a loss or gain of heat. This change in heat is called enthalpy. The goal of this experiment is to calculate enthalpy for three different reactions. To calculate the enthalpy of a reaction, a calorimeter is used to measure the change in heat energy from mixing different substances. The change of temperature is found by comparing the change in temperature of the system to the temperature of the surroundings. For a calorimeter, a Styrofoam cup place in a beaker…

Words: 840 - Pages: 4
• ###### Essay The Measure Of A Disorder

represent the measure of a disorder of a system. In 1909, Heike Kamerlingh Onnes was credited with placing the term enthalpy in scientific literature. Enthalpy is a measure of the heat content of the system at constant pressure . Entropy and enthalpy differ because they are two different quantities, characterized by the measure of disorder and the measure of heat, respectively. Entropy and enthalpy are the driving forces of thermochemistry and determine the cyclic forces of life. One of the common phrases…

Words: 1071 - Pages: 5
• ###### Essay on Chem 1212l Borax Experiment

Chem 1212L-345 Lab report Experiment #20: Temperature Change and equilibrium Woochul Jin Jeeyoon Kong, Alla Asmerom Hagos 03/22/2011 Woochul Jin Chem 1212L-345 Experiment #20 Lab Report Temperature change and equilibrium Introduction: In this experiment, we will find out how the variation of the value of an equilibrium constant with temperature can be used to determine the enthalpy (heat), entropy (randomness), and free energy (G) changes associated with the system in question…

Words: 1438 - Pages: 6
• ###### Enthalpy & Entropy Essay

Experiment ENTHALPY AND ENTROPY OF ZINC WITH COPPER SULFATE The CCLI Initiative Computers in Chemistry Laboratory Instruction LEARNING OBJECTIVES The learning objectives of this experiment are to. . . ! ! determine changes in enthalpy and entropy of the reaction of zinc with copper sulfate using two methods: electrochemistry and calorimetry. compare the enthalpy values obtained by the two methods. BACKGROUND Thermodynamics is concerned with energy changes that occur in chemical and physical process…

Words: 1811 - Pages: 8
• ###### Thermochemistry Essay

Thermochemistry Lab Purpose: This lab taught procedures for determining heat of capacity of a calorimeter and measuring enthalpy of change for three reactions. It also enforced methods of analyzing data obtained through experimentation and calculating enthalpy. These procedures are used in the branch of thermodynamics known as thermochemistry which is the study of energy changes that accompany chemical reactions. Concepts from this lab can be used to determine the potential energy of a chemical…

Words: 2435 - Pages: 10
• ###### Essay The Heating Value Of A Substance

“Calorimetry is the science associated with determining the changes in energy of a system by measuring the heat exchanged with the surroundings. Calorimetry labs are frequently performed in order to determine the heat of reaction or the heat of fusion or the heat of dissolution or even the specific heat capacity of a metal. These types of labs are rather popular because the equipment is relatively inexpensive and the measurements are usually straightforward. A calorimeter is a device used to measure…

Words: 1301 - Pages: 6
• ###### Never Give Up Essay

40 460 Total Marks 100 100 100 100 100 100 50 50 50 100 850 Credits Strength of Materials- I Theory of Machines-I Machine Drawing Applied Thermodynamics -I 4 4 4 5 4 3 1 1 2 1 29 Manufacturing Processes – I Engineering Materials & Metallurgy Engineering Materials & Metallurgy Lab BTME308 Strength of Materials Lab. BTME309 Applied Thermodynamics Lab Advisory Meeting BTME 310 Workshop Training* Total * Workshop Training will be imparted in the Institution at the end of 2 nd semester for…

Words: 7949 - Pages: 32
• ###### Essay on Jntuk 2-1 and 2-2 Mech Syllabus R10

MECHANICAL ENGINEERING - COURSE STRUCTURE – 2010 BATCH 1 2 3 4 5 6 7 8 9 I SEMESTER Engineering Mechanics Fluid Mechanics & Hydraulic Machinery Thermodynamics Managerial Economics & Financial Analysis Electrical & Electronics Engineering Computer aided Engineering Drawing lab Electrical & Electronics Engg. Lab Fluid Mechanics & Hydraulic Machinery Lab English Communication Practice P 4 4 4 4 4 6 3 3 2 II YEAR C II SEMESTER 4 1 Kinematics of Machinery 4 2 Thermal Engineering -I 4 4 4 4 2 2…

Words: 5061 - Pages: 21