Which of the following liquids is least viscous? Assume temperature is 25°C.

The story behind the answer

Viscosity measures a liquid’s resistance to flow; lower means it runs more easily. At 25°C, acetone’s dynamic viscosity is about 0.32 mPa·s, lower than benzene (~0.65), water (~0.89), and mercury (~1.5). Acetone molecules interact mainly via weak dispersion and