Properties of Matter PDF

# Properties of Matter - Are these properties determined without changing the identity of the substance? - Yes - Physical Properties - No - Chemical Properties - Does the property depend on the amount of substance? - Yes - Extensive Properties - Mass - Volume -...

# Properties of Matter - Are these properties determined without changing the identity of the substance? - Yes - Physical Properties - No - Chemical Properties - Does the property depend on the amount of substance? - Yes - Extensive Properties - Mass - Volume - Length - Shape - No - Intensive Properties - Color - Melting Point - Boiling Point - Density ## How does the substance react to the presence of? - Air - Acid - Base - Water - Other Chemicals # States of Matter - Gases, liquids, and crystalline solids are the three states of matter. - The molecules, atoms, and ions in the solid state are held in close proximity by intermolecular, interatomic, or ionic forces. - Solids with high vapor pressures, such as iodine and camphor, can pass directly from the solid to the gaseous state without melting. This process is known as sublimation. - The reverse process, that is, recondensation to the solid state, may be referred to as deposition. - Mesophase (Greek, mesos, middle), which lies between the liquid and crystalline states. This so-called liquid crystalline state # Particle Properties | Phase | Proximity | Energy | Order | Volume | Shape | |---|---|---|---|---|---| | Solid | close | little | ordered | definite | definite | | Liquid | close | moderate | disordered | definite | indefinite | | Gas | far apart | a lot | Very disordered | indefinite | indefinite | For measuring of the matter the volume and mass are used. - **Gases**: The average kinetic energy of the gas molecules is much larger than the average energy of the attractions between them. - **Liquids**: The intermolecular attractive forces are strong enough to hold the molecules close together, but without much order. - **Solids**: The intermolecular attractive forces are strong enough to lock molecules in place (high order). # 1. The Gaseous State - Owing to vigorous and rapid motion, gas molecules travel in random paths, frequently colliding with one another and with the walls of the container in which they are confined. - The temperature involved in gas equations is given in absolute or Kelvin degrees (K). Zero degrees on the centigrade scale is equal to 273.15° К. - Gas can be compressed - Gas exerts pressure on whatever surrounds them - Gas expands into whatever volume is available - Gas mix completely one another - Gas can be described in terms of their temperature, pressure, the volume occupied, and the amount (number of moles) present P, V, T, n # Physical Pharmacy 1 - State of Matter ## Objectives - **To understand the application of quantitative and theoretical principles of the physical characters of matter to the practice of pharmacy.** - **It helps the pharmacist to predict the solubility, compatibility and biological activity of drug products.** - **As a result of this knowledge, it is helpful in the development of new drugs and dosage forms as well as in the improvement of various modes of administration.** # Binding Forces Between Molecules In order for molecules to exist in aggregates in gases, liquids, and solids, **intermolecular forces** must exist. - **Cohesion**, or the attraction of like molecules, and - **Adhesion**, or/ the attraction of unlike molecules, are manifestations of intermolecular forces. - **Repulsive and Attractive Forces**. When molecules interact, both repulsive and attractive forces operate. - **Moelwyn-Hughes points to the analogy between human behavior and molecular phenomenon.** **Table 2-1: Intermolecular Forces and Valence Bonds** | Bond type | Bond Energy (kcal/mole) | |---|---| | Van der Waals Forces and Other Intermolecular Attractions | 1-10 | | Dipole-dipole interaction, orientation effect, or Keesom force | | | Dipole-induced dipole interaction, induction effect, or Debye force | | | Induced dipole-induced dipole interaction, dispersion effect, or London force | | | Ion-dipole interaction | 2-9 | | Hydrogen bonds: | | | O-H...O | 6 | | C-H...O | 2-3 | | O-H...N | 4-7 | | N...N | 2-3 | | F-H...F | 7 | | Primary - Valence Bond | | | Electrovalent, ionic, heteropolar | 100-200 | | Covalent, homopolar | 50-150 | # 1. Van der Waals Forces - Dipolar molecules frequently tend to align themselves with their neighbors, so that the negative pole of one molecule points toward the positive pole of the next. - **Types of Van der Waals Forces** - dipole-dipole or Keesom forces (Force between two permanent dipoles) - dipole-induced dipole, or Debye, interactions (Force between a permanent dipole and a corresponding induced dipole) - dispersion, (London dispersion force or Van der Waals-London force) (Weak electrostatic force) # A-Dipole-Dipole/Keesom forces - Are the forces that occur between two molecules with permanent dipoles. (Two polar molecules align so that 6+ and 8- are matched (electrostatic attraction) An example of this can be seen in: HCl, fluromethane (CH3F) & KBr # B-Dipole-Induced Dipole - A dipole can induce (cause) a temporary dipole to form in a non-polar molecule, the molecules then line up to match 8+ and 8- charges. # C-London Dispersion Forces - A temporary dipole forms in a non-polar molecule...which leads to a temporary dipole to form in ANOTHER non-polar molecule. - Dispersion is the ONLY intermolecular attraction that occurs between nonpolar molecules # Review - **Dipole - Dipole:** Between two polar molecules - **Dipole - Induced Dipole:** b/w a polar & a non-polar molecule - **Dispersion:** Between two non-polar molecules # 2-Ion Dipole Forces - The force of attraction between an ion and a polar molecule. NaCl breaks up because the ion dipole with water is stronger than the attraction of Na+ to Cl. # 3-Ion Induced Dipole Forces - The force of attraction between an ion and weak dipole which are induced in non-polar molecules. - **Example:** - An ionic substance in anon-polar solvent (NaCl in hexane) - Iodine with potassium iodide # 4. Hydrogen Bonds - The interaction between a molecule containing a hydrogen atom and a strongly electronegative atom such as fluorine, oxygen, or nitrogen is of particular interest. - Hydrogen bonding affects physical properties (mp, bp, solubility) of substance. About one sixth of the hydrogen bonds of ice are broken when ice convert to liquid state and all are destroyed when it vaporize. - **Example**: Water, H-F------H-F, salicylic acid - **Bond Energy:** - Ionic 100-200 Kcal/mole - Covalent 50-150 Kcal/mole - H-bond 2-7 Kcal/mole - Van der Waals forces 1-10 Kcal/mole - Hydrogen bonds are relatively weak, having a bond energy of about 2 to 8 kcaVmole as compared with a value of about 50 to 100kcal for the covalent bond and well over 100~ fer the ionic bond. - The metallic bond, representing a third type of primary valence, will be mentioned in connection with crystalline solids. **Table 2-2: Energies Associated with Molecular and Iconic Interactions** | Compound | Orientation | Induction | Dispersion | Total Energy | |---|---|---|---|---| | H₂O | 8.69 | 0.46 | 2.15 | 11.30 | | HCI | 0.79 | 0.24 | 4.02 | 5.05 | | HI | 0.006 | 0.027 | 6.18 | 6,21 | | NaCl | | | 3.0 | 183 | # Covalent Bonding - Takes place between atoms with small differences in electronegativity which are close to each other in periodic table (between non-metals and non-metals). - The covalent bonding is formed by sharing of electrons (i.e., s and p electrons) between atoms rather than by electron transfer. - This bonding can be attained if the two atoms each share one of the other´s electrons. # Ionic Bonding - Ionic bonding is the electrostatic force of attraction between positively and negatively charged ions (between non-metals and metals). - These ions have been produced as a result of a transfer of electrons between two atoms with a large difference in electro negativities. - All ionic compounds are crystalline solids at room temperature. - NaCl is a typical example of ionic bonding. | Are polar molecules involved? | Are ions involved? | Are polar molecules and ions both present? | | |---|---|---|---| | No | No | | London forces only (induced dipoles) Examples: Ar(), 12(s) | | Yes | No | | Dipole-dipole forces Examples: H2S, CHCl3 | | Yes | Yes | No | Hydrogen bonding: Examples: liquid and solid H2O, NH3, HF | | Yes | Yes | Yes | Ion-dipole forces: Example: KBr in H2O | | | | Yes | Ionic bonding Examples: NaCl, NH4NO3 |