CHEM 1150 Exam 4 Study Guide: States of Matter, Solution Chemistry, and Acids/Bases

Chapter 7: States of Matter and Their Attractive Forces

Gas Laws and Pressure Units

The behavior of gases is described by several laws and concepts, including the kinetic molecular theory (KMT) and various pressure units.

• Pressure Units: Common units include atmospheres (atm), millimeters of mercury (mmHg), psi, and kilopascal (kPa).

• Conversions:

  • 1 atm = 760 mmHg = 14.7 psi = 101.325 kPa

• Combined Gas Law: Relates pressure, volume, and temperature of a gas sample. Equation: $\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}$

Kinetic Molecular Theory (KMT) and Ideal Gas Behavior

The KMT explains the properties of gases in terms of particle motion and energy.

• Four Main Points of KMT:

  1. Gases consist of tiny particles in constant, random motion.

  2. Gas particles are far apart relative to their size; most of the volume is empty space.

  3. Collisions between particles and with container walls are elastic (no energy lost).

  4. There are no significant attractive or repulsive forces between particles.

• Ideal Gas: A gas that perfectly follows the KMT assumptions.

Intermolecular Forces (IM Forces)

IM forces are attractions between molecules, influencing physical properties.

• Types of IM Forces:

  • London Dispersion: Weak, temporary forces present in all molecules, especially nonpolar.

  • Dipole-Dipole: Attractions between polar molecules.

  • Hydrogen Bonding: Strong dipole interaction when H is bonded to N, O, or F.

• Identifying IM Forces: Analyze molecular structure and electronegativity differences.

Physical Properties: Boiling Point, Vapor Pressure, Viscosity

• Boiling Point (BP): Temperature at which vapor pressure equals atmospheric pressure.

• Vapor Pressure: Pressure exerted by a vapor in equilibrium with its liquid.

• Viscosity: Resistance to flow; higher IM forces increase viscosity.

• Comparisons: Stronger IM forces lead to higher BP and viscosity, but lower vapor pressure.

IM Forces in Biomolecules and Solubility

• Biomolecules: IM forces stabilize structures (e.g., protein folding, DNA base pairing).

• Solubility: "Like dissolves like"—polar solutes dissolve in polar solvents, nonpolar in nonpolar.

Lipids and Cell Membranes

• Types of Lipids:

  • Fatty Acids: Long hydrocarbon chains with a carboxylic acid group.

  • Triglycerides: Glycerol + 3 fatty acids; main storage form of fat.

  • Phospholipids: Glycerol + 2 fatty acids + phosphate group; major cell membrane component.

  • Cholesterol: Steroid structure; modulates membrane fluidity.

• Fats vs. Oils: Fats are solid at room temperature (more saturated), oils are liquid (more unsaturated).

• Soap, Micelles, Emulsifiers: Amphipathic molecules with both hydrophilic and hydrophobic regions; form micelles to trap nonpolar substances in water.

• Lipid Bilayer: Double layer of phospholipids; hydrophobic tails inward, hydrophilic heads outward; forms the cell membrane.

Chapter 8: Solution Chemistry—Sugar and Water Do Mix

Definitions and Properties of Solutions

• Solution: Homogeneous mixture of two or more substances.

• Solute: Substance dissolved in a solvent.

• Solvent: Substance present in greater amount; dissolves the solute.

• Aqueous: Solution where water is the solvent.

• Colloid: Mixture with intermediate particle size; particles do not settle.

• Suspension: Heterogeneous mixture; particles settle out over time.

• Saturated: Solution holding maximum solute at given conditions.

• Unsaturated: Solution holding less than maximum solute.

Identifying Solution Components and Properties

• Determine solute and solvent by relative amounts.

• Assess saturation by observing if additional solute dissolves.

• Water Properties: Excellent solvent due to polarity and hydrogen bonding.

Solubility and Henry's Law

• Solubility: Amount of solute that dissolves at a specific temperature.

• Gases: Solubility decreases with increasing temperature; increases with pressure.

• Solids: Solubility usually increases with temperature.

• Henry's Law: The solubility of a gas in a liquid is proportional to the pressure of the gas above the liquid. Equation: $C = kP$ where C = concentration, k = constant, P = pressure.

Types of Mixtures and Clarity

• Solution: Clear, homogeneous.

• Colloid: Cloudy, does not settle.

• Suspension: Particles visible, settle out.

• Clear vs. Colorless: Clear means transparent; colorless means no color.

Electrolytes and Dissociation

• Strong Electrolyte: Completely dissociates in water. Example equation: $\mathrm{NaCl} \rightarrow \mathrm{Na}^+ + \mathrm{Cl}^-$

• Weak Electrolyte: Partially dissociates. Example equation: $\mathrm{CH_3COOH} \rightleftharpoons \mathrm{CH_3COO}^- + \mathrm{H}^+$

• Nonelectrolyte: Does not dissociate. Example equation: $\mathrm{C_6H_{12}O_6} \rightarrow \mathrm{C_6H_{12}O_6}$

Concentration Calculations

• Percent Composition:

  • Mass/mass (m/m): $\frac{\text{g solute}}{\text{g solution}} \times 100$

  • Volume/volume (v/v): $\frac{\text{mL solute}}{\text{mL solution}} \times 100$

  • Mass/volume (m/v): $\frac{\text{g solute}}{\text{mL solution}} \times 100$

• ppm: $\frac{\text{mg solute}}{\text{kg solution}}$

• ppb: $\frac{\text{\mu g solute}}{\text{kg solution}}$

• Molarity (M): $\frac{\text{mol solute}}{\text{L solution}}$

• Equivalents: Amount of ion that supplies 1 mole of charge. Calculation: $\text{Eq} = \text{mol ion} \times \text{charge}$

• Dilution Equation: $C_1V_1 = C_2V_2$

Membranes and Transport

• Semipermeable Membrane: Allows certain molecules to pass.

• Isotonic: Equal solute concentration inside and outside cell.

• Hypotonic: Lower solute outside; water enters cell (hemolysis).

• Hypertonic: Higher solute outside; water leaves cell (crenation).

• Osmosis: Diffusion of water across a semipermeable membrane.

• Diffusion: Movement from high to low concentration.

• Active Transport: Requires energy to move substances against gradient.

• Facilitated Transport: Uses proteins to move substances down gradient.

• Osmotic Pressure: Pressure needed to stop osmosis. Equation: $\pi = MRT$ where $\pi$ = osmotic pressure, M = molarity, R = gas constant, T = temperature.

Chapter 9: Acids, Bases, and Buffers in the Body

Definitions and Theories of Acids and Bases

• Arrhenius Acid: Produces H+ in water.

• Arrhenius Base: Produces OH– in water.

• Bronsted-Lowry Acid: Proton (H+) donor.

• Bronsted-Lowry Base: Proton (H+) acceptor.

Strong Acids and Bases

• Strong Acids (memorize): HCl, HBr, HI, HNO3, HClO3, HClO4, H2SO4

• Strong Bases (memorize): LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, Ba(OH)2

Naming Acids

• Hydro+ic acid: For binary acids (e.g., HCl = hydrochloric acid).

• +ic acid: For polyatomic ions ending in -ate (e.g., HNO3 = nitric acid).

• +ous acid: For polyatomic ions ending in -ite (e.g., HNO2 = nitrous acid).

Neutralization and Equilibrium

• Neutralization: Acid + base → salt + water. With carbonates: Acid + carbonate → salt + water + CO2

• Equilibrium Constant (Keq): Equation: $K_{eq} = \frac{[\text{products}]}{[\text{reactants}]}$

• Comparing K Values: Larger K = more products at equilibrium; smaller K = more reactants.

• Le Châtelier’s Principle: System shifts to counteract changes in concentration, pressure, or temperature.

Acid Dissociation and Conjugate Pairs

• Weak Acid Dissociation: Example: $\mathrm{HA} + \mathrm{H_2O} \rightleftharpoons \mathrm{A}^- + \mathrm{H_3O}^+$

• Ka Expression: $K_a = \frac{[\mathrm{A}^-][\mathrm{H_3O}^+]}{[\mathrm{HA}]}$

• Conjugate Acid-Base Pairs: Differ by one H+ (e.g., NH3/NH4+).

Autoionization of Water and pH Calculations

• Autoionization of Water: Equation: $2\mathrm{H_2O} \rightleftharpoons \mathrm{H_3O}^+ + \mathrm{OH}^-$ or $\mathrm{H_2O} \rightleftharpoons \mathrm{H}^+ + \mathrm{OH}^-$

• Kw Value: $K_w = [\mathrm{H}^+][\mathrm{OH}^-] = 1.0 \times 10^{-14}$ at 25°C

• pH Calculation:

  • $pH = -\log [\mathrm{H}^+]$

  • $[\mathrm{H}^+] = 10^{-pH}$

  • $[\mathrm{OH}^-] = \frac{K_w}{[\mathrm{H}^+]}$

Table: Comparison of Solution Types

Type	Particle Size	Appearance	Settling
Solution	<1 nm	Clear	No
Colloid	1-1000 nm	Cloudy	No
Suspension	>1000 nm	Opaque	Yes

Example: Table salt (NaCl) in water forms a solution; milk is a colloid; muddy water is a suspension.

Additional info: Where the original notes listed only keywords or brief points, full academic explanations, equations, and examples have been added for clarity and completeness.