Intermolecular Forces Lesson Plan PDF

Lesson 1.1 Kinetic Molecular Theory of Matter Have you ever bought an ice cream on a hot summer day? 2 If yes, then you must have noticed how ice cream, when taken out of the freezer, takes a definite shape, but when exposed in the summer heat, slowly loses its fo...

Lesson 1.1 Kinetic Molecular Theory of Matter Have you ever bought an ice cream on a hot summer day? 2 If yes, then you must have noticed how ice cream, when taken out of the freezer, takes a definite shape, but when exposed in the summer heat, slowly loses its form and melts. 3 1. Identify one way in which the experience of buying ice cream on a hot summer day relates to the kinetic Molecular Theory. 2. List 2 properties of ice cream that can be explained by the principle of the Kinetic Theory. 3. Explain how the KMT can help us understand the changes in physical state of ice cream on a hot summer day. 4  Learning Objectives At the end of the lesson, you should be able to do the following: Explain the kinetic molecular theory of matter. Compare and contrast the different states of matter based on the kinetic molecular theory. 5  The Kinetic Molecular Theory (KMT) is a model used to explain the properties of solids and liquids in terms of intermolecular forces of attraction and kinetic energy of individual particles. 6 1. Matter is made of particles that are constantly in motion. This energy in motion is called kinetic energy. 2. The amount of kinetic energy in a substance is related to its temperature. 3. There is space between particles. The amount of space in between particles is related to the substance’s state of matter. 4. Phase changes happen when the temperature of the substance changes sufficiently 5. There are attractive forces in between particles called intermolecular forces. The strength of these forces increase as particles get closer together. 7 Molecules Interact through Attractive Forces The attractive forces between molecules are known as the intermolecular forces. The stronger the interaction between two molecules, the smaller their distance will be. 8 Molecules Interact through Attractive Forces solid liquid gas 9 10 11 Temperature Is a Measure of the Average KE heat increases KE increases 12 Based on the kinetic molecular theory of matter, the state of a matter is determined by two factors— temperature and strength of intermolecular forces. As explained by KMT: At lower temperatures, intermolecular forces determine the state of a substance. Substances with intermediate to strong intermolecular forces will form a condensed phase, either solid or liquid. Those with weak intermolecular forces will be in the gaseous state. 14  Check Your Understanding Identify the terms described in each of the following item. 1. This theory explains how microscopic parameters relate to macroscopic properties of matter. 2. The state of matter which is rigid. It has a definite shape and volume, and is not compressible 15  kinetic intermolecular energy forces Liquids have more kinetic energy than solids So, the intermolecular forces between liquid particles tend to be weaker 16 1. The shape and volume of gases are not definite because molecules are widely separated, have negligible attraction for one another and are constantly moving rapidly in all directions so they can fill any shape and size of container. 2. Liquid molecules are close enough to keep neighboring molecules in a fixed position. They have attractive forces to keep them together so that the total volume of a certain amount of them is definite. Since they can still move , slipping and sliding over one another, the liquids continues to conform to the shape of its container. 3. Solid particles are closely packed because of strong attractive forces among them. Their low kinetic energies caused them to stay in fixed position, resulting in definite shape and volume. 17  Criteria Sold Liquid Arrangement Movement Held by very strong Held together by strong forces of attraction forces of attraction Particles are not free to Particles are able to move slide past one another Particles vibrate about on fixed position Density Very high High Diffusibility Extremely low Slow Compressibility Least compressible Slightly compressible Volume and Shape Has fixed volume and Assumes the shape of shape the container and has fixed volume Thermal Expansibility Expands slightly when Expands slightly when heated heated 18  Check Your Understanding Identify the terms described in each of the following item. 1. This theory explains how microscopic parameters relate to macroscopic properties of matter. 2. The state of matter which is rigid. It has a definite shape and volume, and is not compressible 19  Check Your Understanding Identify the terms described in each of the following item. 3. This term refers to the interactions between particles. 4. This is a measure of the average kinetic energy of particles. 5. Matter is composed of small ________________. 20  Check Your Understanding Write T if the statement is true. Otherwise, write F is composed of small particles. 1. Matter 2. The particles comprising matter is stationary. 3. The speed at which the particles is moving depends on the temperature. 4. Solids have particles farthest from one another. 5. Gases have strong intermolecular forces 6. Liquids have the largest distances between particles. 21  Check Your Understanding Write T if the statement is true. Otherwise, write 7. F temperature, the kinetic energy of the particles At low determines the physical state. 8. At high temperatures, the particles are most likely to form the closest possible arrangement. 9. Both kinetic energy and intermolecular forces affect the physical state of matter. 10. At higher temperatures, molecules tend to move 22 faster. Intermolecular forces 23 At the end of this lesson, you should be able to: Describe the various intermolecular forces and factors that affect their strength Identify the intermolecular forces possible that may operate in a given molecular structure Illustrate the intermolecular forces between molecules of a compound ◦ 24 Direction: Follow the instruction below. 1. Draw the Lewis structures of the following molecules with the correct shape around the central atom; 2. indicate each bond’s polarity by drawing an arrow to represent the bond dipole along each bond; 3. determine the molecule’s polarity and indicate this with an arrow to represent the dipole; 4. circle their choice in each box to mark the molecule as polar or nonpolar 25 26 27  Intermolecular Forces Intermolecular forces are attractive forces between molecules. Intramolecular forces hold atoms together in a molecule. Generally, intermolecular forces are much weaker than intramolecular forces. 28 29 London dispersion forces and dipole-dipole forces are collectively known as van der Waals forces of attraction. 30 Johannes van der Waals 31  This type of interaction happens to be present in all types of molecules whether ionic or covalent-polar or nonpolar.  the weakest of the intermolecular force that results from the motion of electrons that creates temporary dipoles in molecules 32 Theseforces can only occur in non-polar molecules The breaking of LDF does not require much energy, they freezes at very low temperature 33 This type of interaction happens to be present in all types of molecules whether ionic or covalent-polar or nonpolar. the weakest of the intermolecular force that results from the motion of electrons that creates temporary dipoles in molecules 34  increasing size of the molecules from the halogen group. 35 36 37 38 39 The partially negative fluoride ions will get attracted to the partially positively charged nitrogen of another nitrogen trifluoride molecule 40 41  Intermolecular Forces 3. Ion-Dipole Forces Attractive forces occur between an ion or charged particle and a polar molecule Ion-Dipole Interaction 42  Ion dipole interaction is very evident when pouring water molecules around sodium ions which is the case when dissolving sodium chloride in water. 43 44  Intermolecular Forces 4. Hydrogen Bond or Hydrogen Bridge  The hydrogen bond is a weak bond formed when a hydrogen with partial positive charge is close to an atom in a molecule with lone pairs of electron  occurs between polar molecules that contains an oxygen, nitrogen, or fluorine atom covalently bonded to a hydrogen . Relatively strong intermolecular forces.  These types of bonds tend to not follow the relationship between MM and boiling points. 45 46 47  It is not, because if we say the intermolecular type of interaction, we are considering the attraction between molecules not within the molecule 48  Intermolecular Nature of Interaction Strength Forces of Attraction Ion-Dipole Interaction of an ion Strong with the charge end of another molecule Hydrogen Bond A special type of dipole- Medium dipole formed between a partially positive hydrogen and a neighboring molecule with a partially negative N,O,F Dipole-Dipole An interaction between Weak two polar molecules other than N-H, O-H and H-F Dispersion Forces An interaction between Very weak 49 What type(s) of intermolecular forces exist between each of the following molecules? HBr CH4 SO2 50 What type(s) of intermolecular forces exist between each of the following molecules? HBr HBr is a polar molecule: dipole-dipole forces. CH4 CH4 is nonpolar: London dispersion forces. S O SO2 O SO2 is a polar molecule: dipole-dipole forces. 51  Directions: Mark check (/) on the box if the substance is polar/nonpolar, has Ion-dipole Forces, London Dispersion, Dipole-Dipole, and Hydrogen Bonding Forces 52 1. CCl4 5. BF3 2. CO2 6. NH3 3. H2O 7. CF4 4. CH4 8. CH3F Number of valence electron C–4 O–6 N-5 Cl – 7 B-3 H–1 F-7 53 1. CCl4 london df 5. BF3 london df 2. CO2 london df 6. NH3 hydrogen bond 3. H2O hydrogen bond 7. CF4 london df 4. CH4 london df 8. CH3F dipole-dipole 54 55 56 1. Attractive forces that arise between the oppositely charged poles of polar molecules a. London Dispersion forces b. Ion-dipole forces c. Dipole-dipole forces d. Hydrogen bonding 57 2. In which of the following liquids are hydrogen bonds strongest between molecules? a. HBr (l) b. HF (l) c. HCl (l) d. HI (l) 58 3. What is/are the factor/s that affect the state of a substance? a. Temperature only b. Pressure only c. Temperature and Pressure d. Temperature and Volume 59 4. The forces of attraction that exist between nonpolar molecules are called ……. a. London Dispersion forces b. Dipole-Dipole forces c. Ion-dipole forces d. hydrogen bonding 60 5. An attractive force occurs between polar molecules that contains oxygen, nitrogen and fluorine atom. a. London Dispersion forces b. Dipole-Dipole forces c. Ion-dipole forces d. hydrogen bridge 61 III. Explain briefly the following 3 points each 1.How do liquids and solids compare with gases in terms of attractive forces? 2.How are attractive forces related to the motion and amount of kinetic energy of the particles? 62