Solubility And Recrystallization
RESULTS AND CALCULATIONS
Ligroin
Toluene
Ethanol
H2O
Anthracene
Did not dissolve
Slightly dissolved
Did not dissolve
Did not dissolve
Benzoic acid
Did not dissolve
Dissolved
Slightly dissolved
Did not dissolve
Phthalic acid
Almost dissolved
Almost dissolved
Did not dissolve
Dissolved
Resorcinol
Dissolved
Dissolved
Dissolved
Dissolved
Sodium naphthionate
Did not dissolve
Did not dissolve dissolved Dissolved
Table 1. Results for the five compounds tested in four different solvents.
Functional Group
Experimental peak (cm-1)
Literature peak (cm-1)
O-H
3450
3200-3600
O-H
3350-2300
3400-2500
C-H
3100-2600
3200-2800
C=O
1669.6-1600
1710-1720
Table 2. Experimental IR peaks for salicylic acid compared to the literature value.
Percent recovery of salicylic acid
For the first part of the experiment, the compounds which dissolved in the solvent are soluble, while those which are slightly dissolved are moderately soluble and the undissolved ones are not soluble. However, nothing crystallized due to an excess amount of each solvent. For the second part of the experiment, approximately 25 mL of distilled water was combined with 1 g of salicylic acid and it took 6 mL of water to dissolve the sample at the boiling point. When it was crystallized, the product was almost white to colourless and it formed needle-like crystalline structure.
DISCUSSION
The effect of polarity on interactions between the molecules was the focus of the first experiment. For the compounds which dissolved in the solvents used, they were soluble because they have the same polarity, while undissolved ones did not have the same polarity with the solvents used. Anthracene clearly did not dissolve in any of the following solvents, except for toluene but there was only a little effect since it was only slightly dissolved. The same with benzoic acid, it only dissolved in ethanol, while phthalic acid almost dissolved in everything except ethanol. For resorcinol, it dissolved in every solvent used and for
Ligroin
Toluene
Ethanol
H2O
Anthracene
Did not dissolve
Slightly dissolved
Did not dissolve
Did not dissolve
Benzoic acid
Did not dissolve
Dissolved
Slightly dissolved
Did not dissolve
Phthalic acid
Almost dissolved
Almost dissolved
Did not dissolve
Dissolved
Resorcinol
Dissolved
Dissolved
Dissolved
Dissolved
Sodium naphthionate
Did not dissolve
Did not dissolve dissolved Dissolved
Table 1. Results for the five compounds tested in four different solvents.
Functional Group
Experimental peak (cm-1)
Literature peak (cm-1)
O-H
3450
3200-3600
O-H
3350-2300
3400-2500
C-H
3100-2600
3200-2800
C=O
1669.6-1600
1710-1720
Table 2. Experimental IR peaks for salicylic acid compared to the literature value.
Percent recovery of salicylic acid
For the first part of the experiment, the compounds which dissolved in the solvent are soluble, while those which are slightly dissolved are moderately soluble and the undissolved ones are not soluble. However, nothing crystallized due to an excess amount of each solvent. For the second part of the experiment, approximately 25 mL of distilled water was combined with 1 g of salicylic acid and it took 6 mL of water to dissolve the sample at the boiling point. When it was crystallized, the product was almost white to colourless and it formed needle-like crystalline structure.
DISCUSSION
The effect of polarity on interactions between the molecules was the focus of the first experiment. For the compounds which dissolved in the solvents used, they were soluble because they have the same polarity, while undissolved ones did not have the same polarity with the solvents used. Anthracene clearly did not dissolve in any of the following solvents, except for toluene but there was only a little effect since it was only slightly dissolved. The same with benzoic acid, it only dissolved in ethanol, while phthalic acid almost dissolved in everything except ethanol. For resorcinol, it dissolved in every solvent used and for
References: Buchanan, G.W. "Solubility Tests and Recrystallization." CHEM 2203/2204 Organic Chemistry Laboratory Manual. By C.A. White. N.p.: n.p., n.d. 21-31. Print. "IR Spectrum." Research Gate. N.p., n.d. Web. 08 Oct. 2014. Wagner, Kathryn. "Like Dissolves Like." LIKE DISSOLVES LIKE (n.d.): n. pag. Web.