Explain the following observations: (a) The surface tension of \(\mathrm{CHBr}_{3}\) is greater than that of \(\mathrm{CHCl}_{3} .\) (b) As temperature increases, oil flows faster through a narrow tube. (c) Raindrops that collect on a waxed automobile hood take on a nearly spherical shape. (d) Oil droplets that collect on a waxed automobile hood take on a flat shape.

(a) CHBr3 has a greater surface tension than CHCl3 due to its larger, heavier bromine atoms, which result in stronger dispersion forces in the molecule. (b) Oil flows faster through a narrow tube as temperature increases because the increase in kinetic energy weakens its intermolecular forces, resulting in decreased viscosity. (c) Raindrops on a waxed automobile hood form a nearly spherical shape due to the surface tension of water, which minimizes the droplet's surface area to achieve a lower energy state. (d) Oil droplets on a waxed automobile hood form a flat shape due to the difference in intermolecular forces between oil and water, causing the oil to spread out and maximize contact with the hydrophilic waxed surface.