Which combination of properties would be predicted to lead to the most viscous liquid?

• A. Strong intermolecular forces and high molecular weight
• B. Strong intermolecular forces and low molecular weight
• C. Weak intermolecular forces and high molecular weight
• D. Weak intermolecular forces and low molecular weight

Answer: (A)

Verified step by step guidance

1. Understand that viscosity is a measure of a liquid's resistance to flow, which depends on how strongly the molecules interact and how easily they move past each other.
2. Recognize that strong intermolecular forces (such as hydrogen bonding, dipole-dipole interactions, or London dispersion forces) increase viscosity because molecules stick together more tightly, making flow more difficult.
3. Consider molecular weight: higher molecular weight generally means larger molecules, which can become entangled or have more surface area for intermolecular interactions, also increasing viscosity.
4. Analyze each combination: liquids with strong intermolecular forces and high molecular weight will have both strong attractions and large, possibly entangled molecules, leading to higher viscosity.
5. Conclude that the combination of strong intermolecular forces and high molecular weight is predicted to produce the most viscous liquid.