Consider before watching the videos:

In what way is a crystal different from a powder?

Lab Experiments (Write protocols based on the videos then complete your protocols as you perform experiments in class):

1. Cream of tartar crystallization

 

Lab Technique videos (Use these if you need help with your measurements)

1. Weighing

 

Data analysis and calculations (Use these if you need help with your data and calculations)

1. Recovery Yield

The pre-lab will be due before your lab class meets and must include Experimental Protocol, Chemical Table and Equipment Table. The actual numbers will be adjusted based on your starting mass of cream of tartar.

(Analysis) Watch the experiment videos. Take notes on the protocols. Stop the videos and re-watch as necessary to acquire 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 follow, so be detailed.

(Analysis) Identify the equipment (type AND size) needed for the experiment and include the name and an image (picture) 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

(Acquiring competencies) Following your detailed protocol, 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.

1. (Representation) Write the chemical formula for cream of tartar.
2. (Manipulation) Calculate the actual recovery yield using the formula below (HINT: you will use the experimentally recovered amount of cream of tartar for the final grams).
3. (Existing knowledge, research and views) Indicate the solubility of cream of tartar at room temperature and reference your source.
4. (Existing knowledge, research and views) Indicate the solubility of cream of tartar at the boiling point of water and reference your source.
5. (Manipulation) Calculate the mass of cream of tartar that can be dissolved at room temperature in the volume of water you used for the recrystallization.
6. (Manipulation) Calculate the mass of cream of tartar that can be dissolved at the boiling point of water in the volume of water you used for the recrystallization.
7. (Manipulation) Calculate the maximum amount of cream of tartar you could have recovered (HINT: it is the difference in mass of cream of tartar that can be dissolved at room temperature and at the boiling point of water).
8. (Manipulation) Calculate the theoretical recovery yield using the formula below (HINT: you will use the calculated maximum amount of cream of tartar for the final grams).
9. (Analysis) Compare the actual and the theoretical % recovery yields and provide at least one supported argument for the similarity or difference.
10. (Analysis) Comment on the appearance of the starting material compared to the product.
11. (Analysis) Comment on the necessity for drying the crystals before recording the final mass.
12. (Existing knowledge, research and views) Describe what happens with cream of tartar when heated and reference your source.
13. (Experimental Design) Identify a suitable method of drying your cream of tartar crystals without decomposing.
14. (Analysis) Comment on the purpose of the recrystallization, since you start and end with the same material.
15. (Existing knowledge, research and views) Describe at least two uses for cream of tartar.
16. (Analysis) Identify at least one of the 12 principles of green chemistry applied in this experiment. Justify your selection. 12 Principles of Green Chemistry
17. (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 ...
Cream of tartar dissolves faster in hot water	Dissolve it in cold water and compare with hot
Crystals will form at room temperature or colder temperatures	Place a saturated solution in the fridge

   

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. Purification of Cream of Tartar through Hot Filtration and Recrystallization

(This is a highlight of what you learned from performing the experiment and processing your collected data. Below is a template and an example of what you are expected to write.) In this lab experiment we investigated [purpose of your experiment] using [list the materials you worked with] and we found that [present the highlights of your results (include numbers)]. The results [present significant results (your % recovery yield)]. The collected data compares to [draw conclusion about your results compared to other sources (this is the theoretical % recovery yield with comments on how it was determined)]. The [add types of measurement individually] measurement was collected using [describe instrument by sensitivity].   Think through this before writing:

1. Purpose: What were you trying to do?
2. Materials used: What chemicals and materials did you work with?
3. Method: What instruments were used to collect measurements and how were the measurements collected?
4. Results: What did you find out about the objects under study?
5. Significance: What did you learn about the precision and accuracy of your techniques? How do your determined values compare to reported values?

Ex. In this lab experiment we purified potassium hydrogen tartrate through ….. starting with …. grams of ……. and …….. mL of…….. Our % recovery of ….. compares favorably/unfavorably to the estimated theoretical % recovery yield of …... All ….. measurements were collected on…... (repeat as needed to include all instruments).

Part 2.

Title of Protocol (Brief description of the experiment in bold) Ex. Hot Filtration Ex. Recrystallization  

Experimental Protocol

(This is a condensed and organized description of the protocol you actually completed during class. Use the exact amounts of materials and list the exact equipment that you used in performing the experiment. The length of this section depends on the complexity of your experiment, usually 3-4 sentences maximum in one paragraph.)   (For each material and procedure)