Exam IV review sheet
Date: Available from Monday, April 16 to Friday, April 20 (90-minute time limit)
Allowed: calculator, lecture notes, lecture slides, textbook, periodic table handout
Format: a mixture of multiple choice, true/false, short answer, and calculation problems
Coverage: Section 8.4 and chapters 9 and 10 in Ball’s The Basics of General, Organic, and
Biological Chemistry (https://open.umn.edu/opentextbooks/textbooks/40)
Topics that could potentially be covered on the exam (not necessarily exhaustive):
Chapter 8: Solids, Liquids, and Gases (Section 8.4)
- Gas Laws: V vs P; V vs. T; V vs. n – know relationships and practical real-world applications;
- Ideal Gas Law (PV = nRT) – calculations; given three of the variables (and the gas law constant), solve for the fourth; know units each variable must be in.
- Ideal vs. Non-Ideal Gases – practical differences and rational
Chapter 9: Solutions
- Solutions: definition; definition of solvent and solute; types of solutions (examples); relationships between the mass of solution and masses of solvent and solute(s) and why?; relationships between the volume of solution and volumes of solvent and solute(s) and why?
- Soluble vs. Insoluble solutes – what factors predict the solubility of a molecular compound solute in a solvent (“like dissolves like”) and what factors predict the solubility of an ionic compound solute in water (solubility rules); how does temperature generally affect the solubility of solid solutes in water and applications? how does the temperature generally affect the solubility of gaseous solutes in water and applications?
how does pressure affect the solubility of a gas in water and applications?
- Properties of a Solution: what do the properties of a solution depend upon? percent concentration: definition, calculations involving; molarity: definition, calculations involving.
- Colligative Properties: definition; what do they depend on?; examples; effects on physical properties of a solution: predict which solution will have the lower freezing point, predict which solution will have the boiling point; determine direction of osmosis; osmolarity: definition; be able to calculate osmolarity based on formula of compound and given molarity (for covalent compounds: osmolarity = molarity, why?); osmosis: definition; applications of osmosis.
- Chemical Equilibria: irreversible vs. reversible reactions, differences and importance; double-headed arrows to indicate reversible reactions (forward and reverse reactions); the equilibrium state: definition,
Chapter 10: Acids and Bases
- Properties of Acids and Bases: differences and similarities
- Brønsted-Lowry definition of an acid and base: identify based on the transfer (acid) or acceptance (base) of H+; conjugate acid-base pairs: importance and identification; structural requirements of an acid and a base and why?
- Self-Ionization of water: water is amphiprotic: definition; in pure water: [H3O+] = [OH–], acids: [H3O+] > [OH–], bases: [H3O+] < [OH–], calculate [OH–] given [H3O+] or vice versa.
- pH scale: typical range of values, meaning, calculate pH value of a solution given either its [H3O+] or [OH–]
- pH measurements: know common ways to measure or estimate pH of a solution
- pH importance: know several ways the pH of a solution can the structure and behavior of its solutes
- Buffers: definition; composition; importance in regulating pH in industrial and especially biological systems.
Example Calculations (Answer Key will be provided):
- What is the volume (in L) of 1.85 moles of hydrogen gas at a temperature of -15 °C and a pressure of 0.585 atm?
- A solution was prepared by dissolving 12.0 g of Al(NO3)3 in enough water for a total solution volume of 100.0 mL.
- What is the percent concentration (% w/v) of this solution?
- What is the molarity of this solution?
- What is the osmolarity of this solution?
3.) How many grams of Na2SO3 are needed to prepare 125.0 mL of a 0.105 M Na2SO3 solution?