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Define a Solution Summary Activity. Read pp. 266 – 268 Define the following terms: solution, homogeneous mixtures, solute, solvent, alloy, and aqueous solutions How are solutions classified? Utilize p. 266 Table 1 for examples
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Define a Solution Summary Activity • Read pp. 266 – 268 • Define the following terms: solution, homogeneous mixtures, solute, solvent, alloy, and aqueous solutions • How are solutions classified? Utilize p. 266 Table 1 for examples • What are some properties of aqueous solutions? Provide key terms, definitions and examples of each. • Assigned Questions: • p. 269 Practice UC #1, 2, 3, 4, 5, 6, 7
Define a Solution Summary Activity • Read pp. 266 – 268 • Define the following terms: solution, homogeneous mixtures, solute, solvent, alloy, and aqueous solutions • How are solutions classified? Utilize p. 266 Table 1 for examples • What are some properties of aqueous solutions? Provide key terms, definitions and examples of each. • Assigned Questions: • p. 269 Practice UC #1, 2, 3, 4, 5, 6, 7
Define a Solution Summary Activity • Read pp. 266 – 268 • Define the following terms: solution, homogeneous mixtures, solute, solvent, alloy, and aqueous solutions • How are solutions classified? Utilize p. 266 Table 1 for examples • What are some properties of aqueous solutions? Provide key terms, definitions and examples of each. • Assigned Questions: • p. 269 Practice UC #1, 2, 3, 4, 5, 6, 7
Define a Solution Summary Activity • Read pp. 266 – 268 • Define the following terms: solution, homogeneous mixtures, solute, solvent, alloy, and aqueous solutions • How are solutions classified? Utilize p. 266 Table 1 for examples • What are some properties of aqueous solutions? Provide key terms, definitions and examples of each. • Assigned Questions: • p. 269 Practice UC #1, 2, 3, 4, 5, 6, 7
Bonding Forces Intramolecular Forces • “intra” means within • forces that bond atoms and ions within a compound Intermolecular Forces • “inter” means between • responsible for how molecules arrange themselves in an orderly fashion (i.e. lattice structure) • relatively weak compared to intramolecular (e.g. covalent bonds) Explaining Solutions
Polar Covalent Bonds • when atoms are identical (e.g. Cl2) the electrons are share equally • however, when two different elements form bond the electron sharing is unequal, bonding electrons spend more time near one atom than the other • Ex. H-Cl (because Cl is more electronegative than H, it has a greater ability to attract electrons when bonded and as a result Cl is slightly negative and H is slightly positive) Explaining Solutions
“slightly” is represented by the Greek letter delta () which represents small difference Example: + H – Cl - • In general, if the absolute value of the difference in electronegativities is 1.7 or less the bond tends to be polar covalent (Review p. 83 Table 1 and p. 84 Figure 3) Explaining Solutions
Polar Molecules • if a molecule contains polar covalent bonds, the entire molecule may have a positive end and a negative end. Therefore, called a polar molecule • however, not all molecules with polar covalent bonds are polar molecules (e.g. HCl and CCl4) • Review Guidelines for Predicting Polar and Nonpolar Molecules p. 85 Table 3 Explaining Solutions
Intermolecular Forces van der Waals forces (2 types) • London dispersion forces • exist between ALL molecules, polar or nonpolar • result of temporary shift of electron “cloud” around atoms in molecule, they are short-lived dipoles (lasts tiny fractions of seconds) Explaining Solutions
Dipole-dipole forces • forces of attraction between oppositely charged ends of polar molecules • positive end of each molecule attracts negative end of neighbouring molecules (kinda, like a weak version of ionic bond) Explaining Solutions
Hydrogen Bonds • occur among highly polar molecules containing F – H, O – H, and N –H bonds • hydrogen bonds are much stronger than van der Waals • water tends to “stick together” because of these bonds Explaining Solutions
Intermolecular Forces Explaining Solutions
SEATWORK Read and Summarize pp. 273 – 275 • Explaining molecular substances in water • The effects of polarity and hydrogen bonds Read Lab Exercise Predicting High and Low Solubilities (pp. 275-277) - Within a small group answer the Prediction (a) Explaining Solutions
Predicting High and Low Solubilities (pp. 275-277) Highest Solubility - Acetic Acid and Methanol • Molecules are polar • Formation of hydrogen bonds with water molecules High Solubility - Dimethyl ether • Molecule is polar • Presence of oxygen atom means some hydrogen bonding with O-H ends of water molecules Slightly Soluble - Carbon dioxide and Oxygen • Should be non-polar, but oxygen presence means that there is a possibility of some hydrogen bonding with water molecules. Insoluble - Propane and Tetrachloromethane • Nonpolar molecules • Little or no solubility in water, cannot participate in dipole-dipole forces and hydrogen bonding
SEATWORK Assigned Questions p. 277 # 3, 4, 5 Read and Summarize pp. 277 - 279 • Ionic compounds in water • Explaining non-aqueous mixtures • Water – “The Universal Solvent” Explaining Solutions