Which molecules would most likely cause a liquid to have the lowest viscosity?

• A. Large, polar molecules
• B. Small, nonpolar molecules
• C. Small, polar molecules
• D. Large, nonpolar molecules

Answer: (B)

Verified step by step guidance

1. Understand the concept of viscosity: Viscosity is a measure of a fluid's resistance to flow. It is influenced by the size and shape of molecules, as well as the intermolecular forces between them.
2. Consider the effect of molecular size: Larger molecules tend to have higher viscosity because they have more surface area for intermolecular interactions, which can hinder their movement.
3. Evaluate the role of polarity: Polar molecules have stronger intermolecular forces, such as hydrogen bonding or dipole-dipole interactions, which can increase viscosity by making it harder for molecules to slide past each other.
4. Identify the characteristics of nonpolar molecules: Nonpolar molecules have weaker intermolecular forces, such as London dispersion forces, which generally result in lower viscosity compared to polar molecules.
5. Determine the combination that results in the lowest viscosity: Small, nonpolar molecules are likely to cause a liquid to have the lowest viscosity because they have minimal intermolecular forces and less surface area for interactions, allowing them to flow more easily.