In the extraction of an organic compound from a dilute aqueous solution, will the organic solvent form the uppoer or lower layer when each of the following solvent is used?
a. chloroform
b. cyclohexane
c. heptane
d. dichloromethane
I would look up the density of the solvents. I would assume a density of 1.00 g/cc for water since the problem specifies a dilute solution, then compare the density of the solvent with the density of water. Density greater than water the solvent sinks. Density lower than water the solvent floats.
In the extraction of an organic compound from a dilute aqueous solution, the organic solvent will largely determine whether it forms the upper or lower layer when mixed with water. Generally, the density and polarity of the solvent can help determine its layer position.
a. Chloroform: Chloroform (CHCl3) is denser than water and less polar. Therefore, it will form the lower layer when mixed with water.
b. Cyclohexane: Cyclohexane (C6H12) is less dense than water and nonpolar. Consequently, it will form the upper layer when mixed with water.
c. Heptane: Heptane (C7H16) is less dense than water and nonpolar. Like cyclohexane, it will also be found in the upper layer when mixed with water.
d. Dichloromethane: Dichloromethane (CH2Cl2) is denser than water but less polar. However, the density difference is not significant enough to determine its layer position alone. The solubility of the organic compound in water and dichloromethane also plays a role. Depending on these factors, it could be present in either the upper or lower layer when mixed with water.
Please note that in some extractions, multiple steps may be required, and the choice of solvent can be crucial in achieving the desired separation. It is always best to consult the specific solubilities and properties of the compounds involved to determine the most appropriate solvent and the resulting layer position.
To determine whether an organic solvent will form the upper or lower layer in the extraction of an organic compound from a dilute aqueous solution, you need to consider the relative densities of the organic solvent and water.
In general, if the organic solvent has a lower density than water, it will form the upper layer. Conversely, if the organic solvent has a higher density than water, it will form the lower layer.
Let's go through each of the solvents mentioned:
a. Chloroform: Chloroform has a density of 1.49 g/mL, which is higher than water (density = 1.00 g/mL). Therefore, chloroform will form the lower layer.
b. Cyclohexane: Cyclohexane has a density of 0.78 g/mL, lower than water. Hence, cyclohexane will form the upper layer.
c. Heptane: Heptane has a density of 0.68 g/mL, lower than water. Therefore, heptane will also form the upper layer.
d. Dichloromethane: Dichloromethane (also known as methylene chloride) has a density of 1.33 g/mL, higher than water. Thus, dichloromethane will form the lower layer.
Remember, the relative density is an important factor in determining the layering during extraction. You can find the density of different solvents in reference books or online databases.