Chapter 11, Problem 1DE

(a)

Interpretation Introduction

To determine:

The properties in the substances that would be important in the application of transferring power.

Answer to Problem 1DE

Solution:

The important properties are viscosity and volatility of the substances.

Explanation of Solution

The important properties of the three isomers of hexanol are viscosity and volatility.

Hydraulic fluids are used to transfer power in hydraulic machinery such as aircraft flight, controls, excavating equipment and hydraulic brakes. The power is transferred by the fluid which is distributed through hoses and tubes by means of various pumps and valves.
The three isomers of hexanol which are hypothesized to be potentially suitable hydraulic fluids are $1$ -hexanol, $2$ -hexanol and $3$ -hexanol.

Viscosity is an important property. As hydraulic fluid distributes through various pumps and valves, so viscosity is an important property. Another important property is volatility as hydraulic fluid works over a range of temperatures.

Conclusion

The important properties are viscosity and volatility of the substances.

(b)

Interpretation Introduction

To determine:

The description of the experiments that determine which of the three alcohols is best suited for use as a hydraulic fluid.

Answer to Problem 1DE

Solution:

The best suited alcohol is $2$ -hexanol.

Explanation of Solution

Viscosity is the resistance of a liquid to flow. To calculate the viscosity of the three alcohols, steel balls experiment will be carried out. Viscosity is determined by measuring the rate at which steel ball fall through the liquid. As the viscosity increases, the steel ball moves slowly.
In $1$ -hexanol, the atoms are arranged linearly and make more contact with each other than the other two alcohols. The intermolecular attractive forces present are very strong due to strong hydrogen bonding. Therefore, its viscosity is highest. Other two alcohols are branched. Hence their viscosity are lower than $1$ -hexanol. Viscosity of $3$ -hexanol is lowest. Therefore the best suited alcohol is $2$ -hexanol because of its medium viscosity.

Conclusion

The best suited alcohol is $2$ -hexanol.

(c)

Interpretation Introduction

To determine:

The hypothesis of the properties that would change from a hexanol to hexanediol and whether experimental procedures be used to explore these properties for hexanediols.

Answer to Problem 1DE

Solution:

Due to difference in the intermolecular forces of attraction, the properties of hexanol and hexanediols are different. The experimental procedures cannot be used to explore the properties for hexanediols.

Explanation of Solution

The class of compounds called hexanediols is related to hexanols except that they have two $-\text{OH}$ groups attached to the six carbon backbone.

The viscosity of hexanediols will be different from hexanols. Due to presence of two hydroxyl groups, the hydrogen bonding will be more and the intermolecular force of attraction will be higher in hexanediols.

Due to stronger forces of attraction, hexanediols are mostly solid compounds. The above experimental procedure used to determine the viscosity of hexanols cannot be used for hexanediols because hexanediols are organic solids and the metallic balls does not flow through them.

Conclusion

The experimental procedures cannot be used to explore the properties for hexanediols.