Consider before watching the videos:   What happens to the mass of two liquids when you combine them?What about their volume?  

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

1. Density of Ethanol/Water solutions

 

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

1. Density of Solutions
2. Density of Solutions-Graphing

 

The prelab is due before your lab class meets and must include Experimental Protocol, Chemical Table and Equipment Table.

(Analysis)Write out the protocol for each part of the experiment. (It can be written in sequentialsteps. Complete sentences are notnecessary.) 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.

Data collection for:	Mass graduated cylinder	Water starting volume reading burette	Water ending volume reading burette	Mass water and cylinder	Ethanol starting volume reading burette	Ethanol ending volume reading burette	Mass graduated cylinder + water + ethanol	Final volume of solution in graduated cylinder
Solution 1
Solution 2
Solution 3

 

(Representation) Write the balanced equation for the mixing of ethanol in water.

1. (Analysis) Classify the mixing of ethanol in water as a physical or chemical process and use your equation to justify your choice.
2. (Manipulation) Calculate the density of water using the mass of water and the volume of water released from the burette from your last solution. Consider units and significant figures.
3. (Representation) Fill in the following table with your water density values.

Solution number	Mass water (g)	Volume water (mL)	Density water (g/mL)
Solution 1
Solution 2
Solution 3

 

5. (Manipulation) Calculate the density of ethanol using the mass of ethanol and the volume of ethanol released from the burette from your last solution. Consider units and significant figures.
6. (Representation) Fill in the following table with your ethanol density values.

Solution number	Mass ethanol (g)	Volume ethanol (mL)	Density ethanol (g/mL)
Solution 1
Solution 2
Solution 3

 

7. (Manipulation) Calculate the density of your first mixture, using the combined mass of water and ethanol and the combined volume recorded in the graduated cylinder. Consider units and significant figures.
8. (Representation) Fill in the following table.

Solution number	Mass ethanol (g)	Mass of water (g)	Mass of water and ethanol (g)	Volume mixture from graduated cylinder (mL)	Density of mixture (g/mL)
Solution 1
Solution 2
Solution 3

 

9. (Manipulation) Calculate the % mass of ethanol for your first mixture. Consider units and significant figures.
10. (Representation) Fill in the following table:

Solution components	Mass ethanol (g)	Mass of water (g)	Mass water + ethanol (g)	% mass ethanol (%)
Solution 1
Solution 2
Solution 3

 

11. (Interpretation) Using the calibration curve below, identify the expected density values for the ethanol compositions in your mixtures.
12. (Representation) Add your calculated data points on the calibration curve below in a different color. You may create your own chart using Excel.

         

13. (Manipulation) Calculate the % volume lost in your first mixture by subtracting the volume measured in the graduated cylinder from the combined volume for water and ethanol dispensed from the burettes.
14. (Representation) Fill in the following table:

Solution number	Volume water added (mL)	Volume of ethanol added (mL)	Total calculated volume of solution from burettes: volume of ethanol + volume of water added (mL)	Total actual volume of solution read from graduated cylinder (mL)	Difference between actual and calculated volumes (volume lost on mixing) (mL)
Solution 1
Solution 2
Solution 3

 

15. (Analysis) Identify at least one of the 12 principles of green chemistry applied in this experiment. Justify your selection. 12 Principles of Green Chemistry
16. (Assumptions) Fill in the following table using the data and observations from your experiment:

Assumptions made	Testing the assumption	If assumptions are wrong ...
The distilled water is pure	Evaporate it and check for residue	The density would change depending on the density of the contaminant
100% ethanol does not pick up water from the air

 

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. Solution Density Principles: Ethanol-Water Mass/Volume Interactions  

(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]. The collected data compares to [draw conclusion about your results compared to other sources (this could be another group or the literature value)]. The [add type 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 investigated a nonlinear relationship between density and percent mass using ethanol-water solutions. The mass of the ethanol was determined to range from…. to …. g.  The mass of the water was determined to range from…. to …. g. The volume of the ethanol was determined to range from…. to …. mL.  The volume of the water was determined to range from…. to …. mL. The densities of the solutions were found to be within …% of the literature values by composition. The differences of …….. between the actual and calculated solution volumes indicated ……… demonstrating the nonadditive nature of volumes. All mass measurements were collected on digital scales with 0.01 g sensitivity. Volumes were dispensed from a burette with 0.01mL sensitivity into a graduated cylinder of 0.01mL sensitivity.  

Part 2.

Title of Protocol (Brief description of the experiment in bold) Ex. Determining the density of water-ethanol solutions