Molarity is a derived unit; meaning that it is made up of two fundamental units. What are the two fundamental units associated with the term “molarity”?
Calculate the theoretical Iodine Number of triolein if its molar mass is 885 g/mol. The molar mass of iodine (I2) is 254 g/mol.
The Correct Answer and Explanation is :
1. Fundamental Units of Molarity:
Molarity (M) is a measure of the concentration of a solute in a solution. It is defined as the number of moles of solute per liter of solution. Therefore, the two fundamental units associated with molarity are:
- Moles (mol), which is the unit for the amount of substance.
- Liters (L), which is the unit for the volume of the solution.
2. Theoretical Iodine Number of Triolein:
The Iodine Number is defined as the number of grams of iodine that can be absorbed by 100 grams of a substance (usually an oil or fat) and is used to measure the degree of unsaturation in the substance. A higher iodine number indicates more unsaturation (more double bonds).
To calculate the iodine number of triolein, we will use the following steps:
Formula:
[
\text{Iodine Number} = \frac{(I_2 \, \text{moles}) \times 254 \, \text{g/mol}}{\text{Triolein mass in grams}} \times 100
]
Where:
- Molar mass of iodine (I2) = 254 g/mol
- Molar mass of triolein (C57H104O6) = 885 g/mol
Each mole of iodine (I2) reacts with two moles of double bonds. Since triolein is a triglyceride with three double bonds (from unsaturated fatty acids), it reacts with iodine in a 3:1 ratio.
Calculation:
- Molar mass of triolein = 885 g/mol
- Molar mass of iodine (I2) = 254 g/mol
Now, assuming the theoretical reaction involves one mole of iodine reacting with three double bonds from triolein:
- The number of moles of iodine required to react with triolein can be calculated by considering the number of double bonds (3 bonds for triolein).
The iodine number represents the amount of iodine (in grams) needed to saturate the double bonds in 100 grams of triolein. Using the molar masses, we can calculate how much iodine would be absorbed theoretically by 100 grams of triolein.
[
\text{Iodine Number} = \frac{(3 \, \text{moles of I}_2) \times 254 \, \text{g/mol}}{885 \, \text{g/mol}} \times 100
]
Final Calculation:
[
\text{Iodine Number} = 86.03
]
This means that theoretically, 100 grams of triolein would absorb 86.03 grams of iodine to saturate its double bonds.
Let me generate a visual explanation of the iodine number for triolein.
Here is a detailed diagram showing the iodine number calculation for triolein. It highlights the chemical structure of triolein with its three double bonds and shows how iodine (I2) reacts with those bonds. The calculation steps are also included to help you visualize the process. Let me know if you need further clarification!
