Hexane is a hydrocarbon (a molecule containing only carbon and hydrogen) with a molecular weight of 86.18 g/mol,

a density of 0.660 g/mL, and a boiling point of 69C.

Pentanol is an alcohol (a hydrocarbon with a "OH" group attached to one of its carbons) with a molecular weight of
88.15 g/mol, a density of 0.814 g/mL, and a boiling point of 137C.

Calculate the volumes if 2.50 moles of each chemical is present.

Hexane: mL
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Pentanol: mL
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Think about this for the experiment you will perform in lab this week: You calculated the above volumes from the same number of molecules (moles). Why did you end up with two different volumes? The answer goes beyond the differences in the formula weights and densities.

Calculate the mass of 2.5moles of each.

Volume=mass/density

Here is a site about H bonding and water which should translate to the pentanol with no trouble.

http://www.nature.com/nature/journal/v173/n4408/abs/173774a0.html

Molecular Weight multiply by moles and divide by density is the answer!!

To calculate the volumes of Hexane and Pentanol when 2.50 moles of each chemical is present, we can use the equation:

Volume = (moles * molar mass) / density

First, let's calculate the volume of Hexane:

Molar mass of Hexane: 86.18 g/mol
Density of Hexane: 0.660 g/mL
Moles of Hexane: 2.50 moles

Volume of Hexane = (2.50 moles * 86.18 g/mol) / 0.660 g/mL

Now, we can calculate the volume of Pentanol:

Molar mass of Pentanol: 88.15 g/mol
Density of Pentanol: 0.814 g/mL
Moles of Pentanol: 2.50 moles

Volume of Pentanol = (2.50 moles * 88.15 g/mol) / 0.814 g/mL

By substituting these values into the equations, we can easily calculate the volumes in milliliters for each chemical.

Now, let's think about the reason why we end up with different volumes for Hexane and Pentanol, even though we started with the same number of moles.

The volume of a substance depends not only on its molecular weight and density but also on its molecular arrangement and intermolecular forces. Hexane and Pentanol have different molecular structures and types of intermolecular forces, which contribute to their different boiling points and densities. These differences affect the spacing between the molecules and therefore the volume that a certain number of moles would occupy.

In simple terms, the molecules of Hexane and Pentanol pack differently, and this affects how much space they occupy. Hexane molecules are more compactly packed compared to Pentanol molecules, and therefore, more Hexane molecules can occupy the same volume compared to Pentanol molecules. This is why even though we started with the same number of moles, Hexane has a larger volume than Pentanol.

Understanding the relationship between molecular structure, intermolecular forces, and volume is important because it helps us predict the physical properties of different substances, such as boiling points, densities, and volumes.