The physical attributes of Unknown 33A were that it was a white, crystal, and solid that had a sweet cherry smell. As for Unknown 33B, the physical attributes were that it was a beige, yellowish color liquid that was translucent and had a viscosity similar to water. Also, the liquid was homogenous and smelled sour and similar to mildew.
The purpose of using solubility analysis on an unknown is to narrow the possible unknowns given based on the solubility analysis. Acetone was a control for ketone and was soluble in water. Hexanal was a control for an aldehyde and was insoluble in water due to intermolecular forces, such as an increased amount of hydrophobic area rather than hydrophilic area. As a result, by identifying the solubility of the
Take two test tubes, label each test tube according to solvent. Add 1 mL of distilled deionized water to the first test tube and 1 mL of ethanol to the second test tube. Next, add 1 mL of the unknown liquid to each test tube, shake for a small period of time, and observe patiently. During this observation, you will be able to determine whether the two liquids mix completely, slightly, or not at all. If the two liquids mix completely, then you should be able to see one liquid mixed together without a visible line indicating two different substances. This means the two liquids are considered soluble. If the two liquids
Phenacetin’s cold water solubility is 0.076 grams/100 mL of water, whereas its boiling water solubility is 1.22 grams/100 mL of water. In this experiment, water solubility will be an indicator for how much boiling water to use in recrystallization, which purifies the unknown precipitate produced in the second lab. If a substance has higher water solubility in boiling water, such as acetanilide compared
In experiment two, the drug Panacetin was separated by a series of chemical reactions into its three components: sucrose, aspirin, and an unknown active ingredient, either acetanilide or phenacetin. The purpose of this lab was to determine what percentages of each component is present in the pain-killer. The initial step was to dissolve Panacetin in dichloromethane. However, sucrose is insoluble in dichloromethane because organic molecules are soluble in organic solvents, and dichloromethane is an inorganic solvent, so only aspirin and the unknown dissolved. By using gravity filtration, sucrose was filtered from the solution and 0.30g of solid was collected.
The primary goal of this laboratory is to correctly identify an unknown substance. To achieve this task, one may use various tests that reveal both chemical and physical properties of a substance. By comparing the results of a known substance and the unknown substance, one may eliminate alternative possibilities and more accurately predict the undisclosed compound. Furthermore, by performing these tests, data can be collected and verified regarding chemical and physical properties of the unknown. Understanding the chemical properties of a known substance aids one’s understanding of the unknown based on comparative analysis of the results of the tests.
As indicated in Table 1, each of the given substances for this lab were soluble in ethyl acetate. However, the solubility results varied based on the structure of each tested compound. 4-bromoacetanilide and fluorene are both insoluble within solvents of HCl and NaOH. Fluorene will stay soluble within the organic layer since its is a purely made of carbon and hydrogen. 4-bromoacetanilide will act similarly given its nonpolarity from balanced branches and lack of acid/basic characteristics. 4-nitroaniline and 2,5-dichloroaniline travel solubly into the HCl/H2O solvent when added to the separatory funnel, yet form a precipitate after a highly concentrated NaOH is added. Both 4-nitroaniline and 2,5-dichloroaniline are slightly basic organic compounds, and when an acid (HCl) is added a proton will transferred to make them ionic. In their ionic state, both compounds become water-soluble. When NaOH is added to 4-nitroaniline and 2,5-dichloroaniline, it removes the proton causing the compounds to become insoluble in water once again. The same concept can be applied in an opposite fashion to the acid organic compounds of 3-chlorobenzoic acid and resorcinol; both become water-soluble when they lose a proton after mixed with NaOH. They go back to their water insolubility if you add an acid to donate a proton back to 3-chlorobenzoic acid and resorcinol. Therefore, after completing this lab,
Both Aspirin and the Unknown are soluble in dichloromethane, due to their non-polar characteristics. To separate the two components, sodium bicarbonate was added (see figure 3). Sodium bicarbonate reacted with aspirin and converted it to a salt, also forming water and carbon dioxide. It was observed that the solution "fizzed" when this reaction took place, showing the release of carbon dioxide. The newly formed salt then traveled to an aqueous layer where it was soluble, while the unknown remained in the dichloromethane layer. The two layers were then separated. To collect an aspirin solid, the combination of the addition of HCl and the process of vacuum filtration helped to break down the salt and form a solid. Then the solid was placed in the Fisher Scientific Biotemp Oven to dry it to a constant mass of 0.091 g, 32.97% of the total composition. The
Samples of benzophenone, malonic acid, and biphenyl were each tested with water, methyl alcohol, and hexane. Benzophenone was insoluble in water as it is nonpolar while water is highly polar. Benzophenone was soluble in methyl alcohol, dissolving in 15 seconds, because methyl alcohol is intermediately polar as benzophenone is nonpolar. Methyl alcohol is polar but not as much as water. Thus, the nonpolar benzophenone was soluble in methyl alcohol. Benzophenone was partially soluble in hexane because hexane is nonpolar as is benzophenone. Thus, benzophenone was dissolved in hexane. Malonic acid was soluble in water because both malonic acid and water are polar. It took 25 seconds for malonic acid to dissolve in water. Malonic acid was soluble in methyl alcohol because malonic acid is polar and methyl alcohol is intermediately polar, allowing malonic acid to dissolve in the methanol in 15 seconds. Malonic acid was insoluble in hexane because hexane is nonpolar while malonic acid is polar. Biphenyl was insoluble in water as water is highly polar whilst biphenyl is nonpolar. Biphenyl was partially soluble in methanol which is intermediately polar whilst biphenyl is nonpolar, allowing it to dissolve a little. Biphenyl was soluble in hexane because both biphenyl and hexane are nonpolar molecules. Biphenyl dissolved in hexane in 10 seconds.
Sucrose is insoluble in the organic solvent dichloromethane (CH2 Cl2). Aspirin, acetanilide, and phenacetin are soluble in dichloromethane but relatively soluble in water. Aspirin reacts with bases such as sodium bicarbonate to form a salt, sodium acetylsalicylate, which is insoluble in water. Acetanilide and phenacetin are not converted into salts by sodium bicarbonate.
6. The solubility of the solids were tested using a micro tray, by placing them in water and oil to observe their polarity,
By identifying the solubility of the unknown, it could lead to a closer interpretation as to what the functional group the unknown may be. Solubility is determined based on intermolecular attractive forces, such as hydrogen bonding, dipole-dipole, and London dispersion forces. Intermolecular attractive forces arise due to different electron environments in different molecules. For example, water molecules are good at dissolving
The purpose of this lab was to identify unknown substances using density. We had three unknown substances; a yellow liquid and two metal rods. For each substance we measured volume using the water displacement method in a graduated cylinder and mass using a triple beam balance. Then we calculated density using the formula density (g/cm3)= mass (g)/volume (cm3). The data we collected in the lab is in the table below. After comparing our data with the density chart we were able to determine the identities of the substances. The liquid was cooking oil and the rods 1 and 2 were copper and aluminium, respectively. In conclusion, density - a characteristic property- is important because even though many substances may look the same but have different
The eluting solvent passed down the column by the gravity and an equilibrium was established between the solute absorbed by the absorbent (silica gel in this experiment) and the eluting solving flowing down. Since the components in the sample had different polarity and they interacted with the stationary phase and the mobile phase differently, the components would be carried by the solvent to a different extent and a separation of the components could be achieved.
Solubility – Very soluble (water), Freely soluble (methylene chloride, chloroform, alcohol), Slightly soluble (acetone) and Insoluble (ether).6 Melting point - 120°C or 248°F.5
Students were given two unknown compounds that were solid and liquid. Unknown 47A was solid that had a white powder with crystal flakes. The smell of Unknown 47A had a vanilla mix with an acidic. For Unknown 47B, it was a liquid and it had a high viscosity. The color of the liquid had a slight brown color to it, but for the most part was colorless. When the light hit towards it, it gives out a rainbow effect. In addition, it had a mild acid smell for Unknown 47B.
Based on the lab’s results, lipids are soluble in both Acetone and Methanol. However, they are more soluble in the Acetone, and only slightly soluble in the Methanol. Because of the chemical structures, this makes sense, since lipids are insoluble in polar solvents (like methanol), but are very soluble in non-polar organic solvents, such as acetone (Hunt).