Thermal Equilibrium
VIDEO LINKS:
Lab Experiments (Write protocols and perform experiments based on these):
Data analysis and calculations (Use these if you need help with your data and interpretations)
The prelab is due before your lab class meets and must include Experimental Protocol, Chemical Table and Equipment Table.
Experimental Protocol
(Analysis) Watch the experiment videos. Take notes on the protocol. Stop the video and re-watch as necessary to acquire the details of the procedure. Write out the protocol for each part of the experiment. (It can be written in sequential steps. Complete sentences are not necessary.) This is the protocol you will follow, so be detailed.
Chemical Table
(Representation) Prepare your chemical table including the materials you will use in the experiment. Here is a general template that you may use.
| Chemical Name | Chemical Formula | Molar Mass (g/mol) | Hazards | reference | PPE |
| Sodium Chloride | NaCl | 58.5 | Skin irritation | https://fscimage.fishersci.com/msds/21105.htm | |
Equipment Table
(Analysis) Identify the equipment (type AND size) needed for the experiment and include the name and an image of each. Be sure to describe the equipment, how to use it, and why it is suitable for this use.
| Equipment Name | Equipment Picture or Description | Intended Purpose |
Data Collection
(Acquiring competencies) Following your detailed protocol based on the videos, perform all the experiments. Record your observations and take pictures of your key steps in the process. Your observations and images need to be incorporated in your data section and this section should be as detailed as possible as you will use this information to complete your discussion.
Data Processing
- (Existing knowledge, research and views) Define thermal equilibrium and provide a specific example to illustrate the concept.
- (Representation) Plot your data for the heat transfer experiment with the metal rod on a graph with temperature on the y-axis and time on the x-axis.
- (Interpretation) Looking at your data for the heat transfer experiment, identify the temperature at thermal equilibrium.
- (Representation) Write the equation for the heat relationship between heat lost by the metal and heat gained by the water.
- (Existing knowledge, research, and views) Identify the specific heat of water with the correct units and a reference.
- (Manipulation) Using your recorded mass for the water, initial and final temperatures for the water and the specific heat of water, calculate the heat absorbed by the water.
- (Manipulation) Using your calculated heat absorbed by the water, find the amount of heat released by the metal.
- (Manipulation) Using your calculated heat released by the metal, mass of the metal and the change in temperature of the metal, calculate the specific heat of the metal.
- (Representation) Write the equation for the dissolution of calcium acetate in water.
- (Representation) Write the equation for the dissolution of calcium chloride in water.
- (Representation) Create a graph with temperature on the y-axis and time on the x-axis. Using two different colors, plot your data for the calcium acetate dissolution and the calcium chloride dissolution.
- (Analysis) Identify each dissolution as endothermic or exothermic and give evidence to support your choice.
- (Interpretation) Look at your data for the dissolution experiment and identify the most extreme temperature (most different from the starting temperature) for the calcium acetate dissolution.
- (Manipulation) Calculate the change in temperature of the solution for the calcium acetate dissolution (this is the difference between the starting and the most extreme temperatures).
- (Manipulation) Using your recorded mass for the water, initial and final temperatures for the water and the specific heat of water, calculate the heat of dissolution for calcium acetate.
- (Manipulation) Calculate the molar enthalpy of dissolution for calcium acetate in both joules and kilojoules.
- (Interpretation) Look at your data for the dissolution experiment, identify the most extreme temperature for the calcium chloride dissolution.
- (Manipulation) Use this value to determine the change in temperature for the dissolution.
- (Manipulation) Using your recorded mass for the water, initial and final temperatures for the water and the specific heat of water, to calculate the heat of dissolution for calcium chloride.
- (Manipulation) Calculate the molar enthalpy of dissolution for calcium chloride in both joules and kilojoules.
- (Existing knowledge, research and views) Identify the molar enthalpy of dissolution for both calcium chloride and calcium acetate from the literature. (references)
- (Manipulation) Calculate the % error for each experimental result.
- (Analysis) Identify at least one of the 12 principles of green chemistry applied in this experiment. Justify your selection. 12 Principles of Green Chemistry
- (Assumptions and Analysis) Fill in the following table using the observations and data from your experiments.
| Assumptions made | Testing the assumption | If assumptions are wrong ... |
| The calorimeter is insulated | ||
Summary
The summary has two parts: an abstract and an experimental protocol reflecting the experiment that you actually performed. The abstract and experimental protocol should both be between 100-250 words, size 12 Arial font each. There may be multiple experimental protocols for one experiment.Part 1.
Title of Experiment: Performed tasks and applied techniques to accomplish the goal of the experiment and a description of the system under study (the title you are given for the lab is insufficient). Ex. Applying calorimetry techniques to …Abstract
Think through this before writing:
- Purpose: What were you trying to do?
- Materials used: What chemicals and materials did you work with?
- Method: What instruments were used to collect measurements and how were the measurements collected?
- Results: What did you find out about the objects under study?
- Significance: What did you learn about the precision and accuracy of your techniques? How do your determined values compare to reported values?