Chapter 12.docx - 1 Chapter 12 notes Chapter 12 Liquids Solids and Intermolecular Forces In this chapter we will discuss the liquid and solid state and

Chapter 12.docx - 1 Chapter 12 notes Chapter 12 Liquids...

This preview shows page 1 - 3 out of 5 pages.

1 Chapter 12 notes Chapter 12 Liquids, Solids and Intermolecular Forces In this chapter we will discuss the liquid and solid state and why these two states behave as they do. Now, to begin with, you already know many things about the three states of matter. Properties of Liquids High densities compared to gases. Indefinite shape. Definite volume. Properties of Solids High densities compared to gases Definite shape Definite volume May be crystalline or amorphous Generalizations of Solids, Liquids, and Gases 1) All gases are either monatomic (He or Ar) or molecules with covalent bonds (N 2 or CO 2 ). 2) All pure liquids at room temperature are composed of molecules with covalent bond (Except for mercury and bromine). Like dissolves like, so polar liquids are miscible with other polar liquids and immiscible with nonpolar liquids. 3) All ionic compounds are crystalline solids at room temperature. Their strong ionic bonds give them high melting points. When molten or dissolved in water, the dissociated ions conduct electricity. Ionic compounds have low solubility in nonpolar liquids. 4) All metals are solids at room temperature, except for mercury. Metals conduct heat and electricity in the solid state. Melting points of metals vary over a wide range. 5) Many molecular (covalently bonded) substances are solids at room temperature. Interionic and Intermolecular Forces Interionic forces are the forces between ions. With a few exceptions, interionic forces are the strongest of all the forces that hold liquids and solids together (Remember the high melting points of ionic solids). This is due to the ions being charged (and having opposite charge). The greater the attraction the higher the melting point. Intramolecular forces are the forces within a molecule due to bonding. Intermolecular forces are the attractions of molecules for one another. We have talked about these before (dipole attraction, hydrogen bonding, and van der Waal’s aka London dispersion forces). These forces tend to be very weak. Liquid State The molecules of a liquid are in constant motion, like those of a gas. Unlike the molecules of a gas, the liquid molecules are restricted by their neighboring molecules. Liquids
Image of page 1

Subscribe to view the full document.

2 Chapter 12 notes can only be compressed slightly. Liquids can diffuse into each other, but the rate is much slower than in gases. The viscosity of a liquid is related to the shape of the molecules that make up the liquid. Liquids that have low viscosity generally consist of small, symmetrical molecules with weak intermolecular forces. Two types of intermolecular forces lead to high viscosity. London dispersion forces (van der Waal’s forces) are responsible for high viscosities of large nonpolar molecules. Hydrogen bonding raises the viscosity of some small unsymmetrical molecules (the molecules have to fulfill the requirements for hydrogen bonding).
Image of page 2
Image of page 3

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Ask Expert Tutors You can ask 0 bonus questions You can ask 0 questions (0 expire soon) You can ask 0 questions (will expire )
Answers in as fast as 15 minutes