1 / 17

The Nature of Liquids

This article explores the nature of liquids, including their definite volume and indefinite shape, ability to flow, and high density compared to gases. It also discusses viscosity and the factors that influence it, such as intermolecular forces and temperature. Furthermore, the concept of surface tension and its importance in capillary action are explained, along with cohesive and adhesive forces.

esthertucker
Download Presentation

The Nature of Liquids

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Nature of Liquids

  2. Properties of Liquids • Definite volume • Indefinite shape • Particles are close together, but they can move a little bit… so liquids can flow. • Density of liquids is much greater than gases. Ex: DH2O(l) is 1250X greater than DH2O(g) at 25C. • Liquids can be compressed… but change in volume is very slight and requires enormous pressure.

  3. Viscosity • Liquids exhibit viscosity. • Viscosity = resistance to flow • Viscosity depends on • strength of intermolecular forces • sizes & shapes of molecules • temperature • The stronger the intermolecular forces, the higher the viscosity. • As temperature , viscosity . • As temperature , viscosity .

  4. Viscosity and Molecular Shape • Carbon tetrachloride, CCl4, consists of small, symmetrical molecules with fairly weak intermolecular forces. It has a low viscosity. • Octadcane, C18H38, consists of long molecules with fairly strong intermolecular forces. It has a relatively high viscosity.

  5. Oil in an engine prevents direct metal to metal contact. • Need a thin film of oil on bearing surfaces to prevent flaking of metal. • If the oil is too thick, it won’t circulate at low temperatures. • If the oil is too thin, it will lose film strength at high temperatures.

  6. Where does the marble drop fastest? Slowest? water glycerol

  7. Surface Tension • Particles at the surface of a liquid exist in an unbalanced environment. No attraction from above to balance attractions from below. • Net attractive force pulling down. • Surface seeks smallest possible area.

  8. Surface Tension • Energy required to increase the surface area by a given amount • Measure of inward pull • Strong intermolecular attractions  HIGH Surface Tension

  9. Surfactants • Compounds that lower the surface tension of water • Disrupt hydrogen bonds between H2O molecules. video

  10. Illustration of Surface Tension

  11. Capillary Action • Water forms a concave meniscus in a glass tube. • Attractive forces between water and glass greater than the attractive forces between the water molecules. • Upward movement of a liquid in a narrow tube is called capillary action.

  12. Cohesive and Adhesive Forces • Cohesive forces are forces of attraction between molecules of a liquid. • Adhesive forces are forces of attraction between molecules of a liquid and anothersubstance. Competition...

  13. Meniscus Force (Hg-glass)  Force (Hg-Hg) Cohesion Adhesion Force (H2O-glass)  Force (H2O- H2O)

More Related