Choose the substance with the highest viscosity

choose the substance with the highest viscosity:
A. C2H4CL2
B. CF4
C. (CH3CH2)2CO
D. C6H14
E. HOCH2CH2CH2CH2OH

I choose E due to increased molar mass and degree of intermolecular forces, dispersion and hydrogen bonding. Is this correct?

Secondly:

Choose the substance with the lowest surface tension:

A. H2O
B. C6H6
C. CH3SH
D. (CH3)2CO
E. CH3CH2CH2CH3

I’ve narrowed my answer down to B & E. A has the highest surface tension carrying the greatest intermolecular forces, C & D have both dispersion forces as well as dipole-dipole leaving me with B & E. Both have dispersion forces present. B has the highest molar mass of the two and possibly the greatest length – which if that is the case it would make E the weakess intermolecular subtance and therefore the subtance with the lowest surface tension. Is that correct?

Thanks for all you help!

Answer

General guidance

Concepts and reason

Viscosity and surface tension of compounds depend on inter molecular forces. If a compound has greater inter molecular forces then their viscosity, and surface tensions will be high. Choose the substances with highest viscosity and lowest surface tension based on their intermolecular forces.

Fundamentals

Viscosity is a property of fluids, it is a measure of its resistance to gradual deformation by tensile strength. Elastic tendency of a fluid’s surface is known as surface tension, surface tension acquires to molecules from their greater attraction to each other. In a molecule, different types of intermolecular forces will be operated depends on their nature. The order of interaction is shown below. Dispersion forces <
Dipole-dipole forces < H- bonding < Covalent forces < Ionic forces

Step-by-step

Step 1 of 2

The substances are С,Н. С1,
2,CF4,(CH,CH,), СО, С,Ни
14, andНОСН,СH,СH,Cн,ОН. Among these substances, the substance with highest viscosity will be НОСН,СH,СH,Cн,ОН.

The substances with highest viscosity will beНОСН,СH,СH,Cн,ОН.


The substanceCF4has dispersion forces due to its non-polar nature, the substanceС,Н. С1,
2has London dispersion forces as it has temporarily polarized, and(CH,CH,), СОhas dipole-diploe forces due to its polar nature, and НОСН,СH,СH,Cн,ОНhas hydrogen bonding as it has more electronegative atom oxygen and shows bond polarity. Dispersion forces <
Dipole-dipole forces < H- bonding < Covalent forces < Ionic forces Among these different types of intermolecular forces, Hydrogen bonding has highest strength. Hence, the substanceНОСН,СH,СH,Cн,ОНhas highest intermolecular forces. So, this is the substance with highest viscosity.

Step 2 of 2

The substances are Н,О,С,Н,,CH,SH, (CH,)Co
32, andCH,CH2CH2CH. Among these substances, the substance with highest surface tension will be CH,CH2CH2CH.

The substances with highest surface tension will beCH,CH2CH2CH.


The substanceС,Н,has dispersion forces, CH,SHand(CH,)Co
32are having dipole-diploe forces, and Н,Оhas hydrogen bonding as it has more electronegative atom oxygen and shows bond polarity. Among these different types of intermolecular forces, Hydrogen bonding has highest strength. Hence, the substanceCH,CH2CH2CHhas highest intermolecular forces. So, this is the substance with highest surface tension.

Answer

The substances with highest viscosity will beНОСН,СH,СH,Cн,ОН.

The substances with highest surface tension will beCH,CH2CH2CH.

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