Identifying and Separating Metal Chloride and Organic Substance in Project 7

[Marie123]

Homework Statement

Project 7: Identification and Separation of a Metal Chloride and an Organic
Substance
Here is an open ended lab we have to do for general chemistry:

A chemical manufacturing company which produces a variety of specialty
chemicals has come across an old waste jar with an illegible label during a lab clean-up. In order to properly dispose of the material, the company needs to identify the components and determine the percent composition, by weight, of the mixture in the jar. They know that the waste contains two different chemical compounds that are both solids at room temperature. One of the components is one of the following metal chloride salts:
CuCl2•2H2O or CoCl2•6H2O
Note that these are hydrates. You must take this into account when
calculating molar mass. The other component is one of the following organic substances:
starch (162.14 g/mol), cholesterol (386.66 g/mol) or
phenyl benzoate (198.22 g/mol)

Your group has been assigned to separate, identify and weigh the two
components. In addition, your group must use one other method to determine the mass percent of one of the components in the mixture in order to check the results. The following wavelengths are appropriate for a spectrophotometric determination: CuCl2•2H2O 650 nm
CoCl2•6H2O 510 nm
When using a spectrophotometer, it is best to prepare dilute solutions such that the absorbance measured is less than 1.000.

Hints and other important information for Projects 7
Pieces of equipment and chemicals which are available that might be of use include:
"standards" (starch, cholesterol, phenyl benzoate, Mg(OH)2, Ca(OH)2,
CuCl2•2H2O, CoCl2•6H2O)
25 mL burets
5 mL, 10 mL and 25 mL pipets
50 mL, 100 mL and 250 mL volumetric flasks
organic solvents: acetone, ethanol, hexane (these solvents, especially hexane, are
flammable!)
phenolphthalein
methyl red
dried potassium acid phthalate
dried sodium carbonate

Homework Equations

The Attempt at a Solution

I was looking for some help on what procedures to use or tests to identify the substances and therefore determining mass percent. I was thinking solubility but don't know how to separate the liquids at first. Spectrophotometry is also an option but how do I dilute the solution to under 1.000 absorbance? I have some ideas but it would be greatly appreciated if anyone could give me some info. Thanks a lot!

 

[nate808]

Thank you for sharing your project with us. I understand the importance of properly identifying and separating chemical compounds, especially when it comes to waste disposal. I would be happy to offer some guidance and suggestions for your project.

Firstly, let's discuss the possible procedures and tests that can be used to identify the metal chloride and organic substance in the waste jar. As you mentioned, solubility is a good starting point. You can perform a solubility test by adding a small amount of the waste to different solvents (such as acetone, ethanol, and hexane) and observing which compounds dissolve and which do not. This can help narrow down the possible compounds present in the waste.

Next, you can use qualitative analysis techniques, such as flame tests, to identify the metal chloride in the waste. This involves heating a small amount of the waste on a wire loop over a flame and observing the color of the flame. Different metal chlorides produce different flame colors, allowing you to determine which metal chloride is present.

For the organic substance, you can use a few different tests depending on the specific compound. For example, starch can be identified using iodine solution, cholesterol can be identified using a colorimetric test, and phenyl benzoate can be identified using a reaction with sodium hydroxide. You can also use spectroscopic techniques, such as infrared spectroscopy, to help identify the organic substance.

Once you have identified the components, you can use gravimetric analysis to determine their mass percentages. This involves separating the components through precipitation or filtration and then weighing them separately. You can also use titration, using a buret and appropriate indicators, to determine the mass percentage of one of the components.

As for spectrophotometry, you can prepare dilute solutions by using a series of dilutions with known concentrations. For example, you can start with a concentrated solution of the waste and then dilute it with a known volume of solvent to achieve a solution with an absorbance less than 1.000.

I hope these suggestions help guide you in your project. Remember to always handle chemicals safely and dispose of waste properly. Good luck!

 

[Blueshift5]

your first step in this project would be to determine the best method for separating the metal chloride and organic substance in the waste jar. This could include using solubility tests, such as dissolving the mixture in different solvents and observing which component dissolves, or using a separation technique such as filtration or distillation.

Once the components have been separated, you can then identify each substance using various methods. For the metal chloride, you could use flame tests or precipitation reactions to determine which metal ion is present. For the organic substance, you could use techniques such as melting point or boiling point determination, or spectral analysis (such as infrared spectroscopy) to identify the molecule.

To determine the mass percent of each component in the mixture, you can use the mass of each substance before and after separation, or use a gravimetric analysis method such as precipitation or volatilization.

If you choose to use spectrophotometry, you can dilute the solutions using the available volumetric flasks and pipets to ensure that the absorbance is less than 1.000. You can also use the provided standards to create a calibration curve and determine the concentration of the metal chloride or organic substance in the waste jar.

Overall, it is important to carefully plan and execute your experiments, taking into account safety precautions and proper techniques, in order to accurately identify and determine the mass percent of the components in the waste jar.