Homework SourseVolume of a stearic acid molecule To find the volume of one
Volume of a stearic acid molecule - To find the volume of one stearic acid molecule requires some assumption as to the shape of an individual, i.e., whether it is cubic, round, cylindrical, etc. Calculate the volume of a single stearic acid molecule assuming the shape is rectangular.
Rectangular: Assume each molecule is a rectangular soild whose height above the surface equals the length of a molecule, but whose cross section in the surface is a sqare with side length equal to one-half the length of a molecule.
My height and length were both 7.68e-8
im just having trouble understand what this question is asking.
Solution
Solution:-The above problem is related to Chemistry, it is not realed to Advance Maths.
But, according to my knowledge I answered to your question.
Stearic acid has the molecular formula C18H36O2.The carbon-Hydrogen bonds are non-polar, while the bonds in the carboxyl group have significant polar character.
Here, we have to find the volume of single stearic acid molecule assuming the shape is rectangular.
To solve this, we have to conduct an experiment and based on the conclusions we have to calculate the volume of a single stearic acid.
Experiment:- If stearic acid molecules are placed on a water surface ,the polar head of the molecule H2 bonds to the water molecules on the surface.The rest of the molecules, the nonpolar trail is not attached to the water, but it attracted to the tails of near by stearic acid molecules ,as a result, the molecules line up on the surface of the water with polar heads on the surface and nonpolar tails on sticking up away from the surface.
If a small number of stearic acid molecules is placed on water, they cover the water with a layer one molecule thick.If more molecules are added, they begin to pile up on the top of one another ,but the first ones added form a monolayer.
The height of the stearic acid molecules above the water is the length of the molecule.You will add ,drop by drop a dilute solution of a stearic acid in hexane, a volatile solvent, to a surface of water. As each drop hits the water, the hexane will evaporate, leaving the stearic acid to spread out the water.
By counting the drops of solution required to cover the surface, you will calculate mass of stearic acid,
Dimensional anlaysis:-
Based upon the above experiment, the following are can be calculated
1.Determining the Avogadro\'s Number from the experimental data.
2,mass of stearic acid monolayer (g) = (Volume of stearic acid solution to form monolayer(mL))X (concentration of stearic acid solution (g/mL) )
Volume of stearic acid solution to form monolayer=( number of drops to form monolayer) / (number of drops in mL)
3)Volume of stearic acid monolayer (cm3) = (mass of the monolayer (gm) ) / (Density of stearic acid g/cm3)
4)Height of monolayer (cm) = (Volume of monolayer (cm3) / (Area of water glass (cm2)
