Name: Period: Date: KIPP NYC College Prep General Chemistry UNIT 12: Solutions Do Now Review Day Concepts/Definitions (1) A solution is made by completely dissolving 40 grams of KCl(s) in 100 grams of water at 50 C. When the solution is cooled to 15 C, how much precipitate forms? g of precipitate Part I: Solubility!!! Show and label the beaker, filled with Kool-Aid (Oh yeah!): Solute Solvent Solution Describe one way to increase solubility of a solid. Describe one way to increase solubility of a gas. Polarity: Explain the phrase Like dissolves like. Part II: Electronegativity and Polarity Molecule H 2 NO 2 CF 4 Polar Bond? H H N O C F Polar Molecule? Dissolve in Water? Difference in electronegativity? Distribution of charge?
Part III: Table F! 1) What type of compound does Table F help determine solubility? 2) LiF soluble or not. Explain reasoning. 3) Calcium phosphate soluble or not. Explain reasoning. Part IV: Table G 1. Determine the mass of HCl to produce a saturated solution at 30 C. 2. Is a 50 g solution of KNO 3 at 40 C unsatured, saturated or saturated with precipitate? 3. How much excess precipitate will be found when 25 g of KClO 3 is cooled to 20 C. Part V: Colligative Properties 1. Colligative properties depend on this: 2. The more concentrated the solution (the more solute) o Freezing point: o Boiling Point Part VI: Molarity 1. Determine the molarity of an NaCl solution containing 5.0 mol in 2.0 L of solution. 2. Determine the number of moles in a 250 ml 2.0 M sucrose solution. 3. Explain how you would create a 1.0 M solution of NaCl in 0.500 L of solution.
CHEMISTRY- UNIT 10 REVIEW: SOLUTIONS Review sheet #1 1. The concentration of a solution can be expressed in (1) milliliters per minute (2) moles per liter (3) grams per kelvin (4) joules per gram 2. A 1-gram sample of a compound is added to 100 grams of H 2O(l) and the resulting mixture is then thoroughly stirred. Some of the compound is then separated from the mixture by filtration. Based on Table F, the compound could be (1) AgCl (3) NaCl (2) CaCl 2 (4) NiCl 2 3. Which phrase describes a molecule of CH 4, in terms of molecular polarity and distribution of charge? (1) polar with asymmetrical distribution of charge (2) polar with a symmetrical distribution of charge (3) nonpolar with an asymmetrical distribution of charge (4) nonpolar with a symmetrical distribution of charge 4. Which formula represents a molecule with the most polar bond? (1) CO (3) HI (2) NO (4) HCl Base your answer to questions 1 on the information below and on your knowledge of chemistry. Rubbing alcohol is a product available at most pharmacies and supermarkets. One rubbing alcohol solution contains 2-propanol and water. The boiling point of 2-propanol is 82.3 C at standard pressure. 1. Explain, in terms of electronegativity differences, why a C O bond is more polar than a C H bond. [1] Base your answers to question 2 and 3 on the information below and on your knowledge of chemistry. The formulas and the boiling points at standard pressure for ethane methane, and methanol, and water are given below. 2. Identify the compound with the strongest intermolecular forces. [1] 3. Explain, in terms of molecular polarity, why the solubility of methanol in water is greater than the solubility of methane in water. [1]
Base your answer to question 4 on the information below and on your knowledge of chemistry. Seawater contains dissolved salts in the form of ions. Some of the ions found in seawater are Ca 2+, Mg 2+, K +, Na +, Cl -, HCO 3 -, and SO 4 2-. An investigation was conducted to determine the concentration of dissolved salts in seawater at one location. A 300.-gram sample of the seawater was placed in an open container. After a week, all the water had evaporated and 10. grams of solid salts remained in the container. 4. At standard pressure, compare the freezing point of seawater to the freezing point of distilled water. [1] Base your answer to questions 4 and 5 on the information below. Ammonium chloride is dissolved in water to form a 0.10 M NH 4Cl(aq) solution. This dissolving process is represented by the equation below. 5. Determine the number of moles of NH 4Cl(s) used to produce 2.0 liters of this solution. [1] 6. Determine the minimum mass of NH 4Cl(s) required to produce a saturated solution in 100. grams of water at 40 C.
CHEMISTRY- UNIT 10 REVIEW: SOLUTIONS Review sheet #2 1. The concentration of a solution can be expressed in (1) milliliters per minute (2) molarity (3) grams per kelvin (4) joules per gram 2. Which compound is soluble in water? (1) Pbs (3) Na 2S (2) BaS (4) Fe 2S 3 3. Which statement explains why a CO 2 molecule is nonpolar? (1) Carbon and oxygen are both nonmetals. (2) Carbon and oxygen have different electronegativities. (3) The molecule has a symmetrical distribution of charge. (4) The molecule has an asymmetrical distribution of charge. 4. The electronegativity difference between the atoms in a molecule of HCl can be used to determine (1) the entropy of the atoms (2) the atomic number of the atoms (3) the first ionization energy of the atoms (4) the polarity of the bond between the two atoms Base your answer to questions 1 on the information below and on your knowledge of chemistry. Rubbing alcohol is a product available at most pharmacies and supermarkets. One rubbing alcohol solution contains 2-propanol and water. The boiling point of 2-propanol is 82.3 C at standard pressure. 1. Explain, in terms of charge distribution, why a molecule of the 2-propanol is a polar molecule. [1] Base your answers to question 2 on the information below and on your knowledge of chemistry. 2. Explain, in terms of intermolecular forces, why isomer 2 boils at a lower temperature than isomer 1. [1]
Base your answer to question 3 on the information below and on your knowledge of chemistry. 3. Explain, in terms of the polarity of sugar molecules, why the sugar dissolves in water. [1] Base your answer to questions 4 on the information below and on your knowledge of chemistry. The compounds KNO 3 and NaNO 3 are soluble in water. 4. Compare the boiling point of a NaNO 3 solution at standard pressure to the boiling point of water at standard pressure. [1] Base your answer to questions 5 on the information below and on your knowledge of chemistry. A 2.50-liter aqueous solution contains 1.25 moles of dissolved sodium chloride. The dissolving of NaCl(s) in water is represented by the equation below. 5. Determine the molarity of this solution. [1] Base your answer to question 6 on the information below and on your knowledge of chemistry. Baking soda, NaHCO 3, can be commercially produced during a series of chemical reactions called the Solvay process. In this process, NH 3(aq), NaCl(aq), and other chemicals are used to produce NaHCO 3(s) and NH 4Cl(aq). To reduce production costs, NH 3(aq) is recovered from NH 4Cl(aq) through a different series of reactions. This series of reactions can be summarized by the overall reaction represented by the unbalanced equation below. 6. Determine the mass of NH 4Cl that must be dissolved in 100.0 grams of H 2O to produce a saturated solution at 70.0 C. [1]