General Chemistry Basics Quiz

General Chemistry Exam Summary

•  The exam contains "basic questions" covering fundamental chemical concepts.
•  Concise answers are provided for each question.
•  Students must answer 5 questions from the list in test format, selecting the correct answer.
•  Some questions may involve simple calculations, the numerical values might vary.
•  The material summarizes crucial "basic" knowledge for the General Chemistry exam.
•  80% efficiency is expected for answering the questions.

Molecular Lattice Characterization

•  Lattice points are occupied by molecules (atoms or isolated molecules).
•  Held together by secondary forces (Hydrogen bonding, dispersion forces, van der Waals interactions).

Atomic Lattice Characterization

•  Lattice points are occupied by atoms bound by strong covalent bonds.
•  Examples include diamond (C), silica (SiO2), red phosphorus (P), silicon (Si), germanium (Ge), and gray/metallic tellurium (Te).
•  Usually characterized by high melting points, high hardness, and are insoluble in most solvents.
•  Do not conduct electricity
•  Often sublimable.

Ionic Lattice Characterization

•  Lattice points are occupied by ions, bound by ionic bonds.
•  Examples include sodium chloride (NaCl), potassium chloride (KCl), magnesium sulfate (MgSO4), potassium fluoride (KF), and lithium bromide (LiBr).
•  Usually have medium to high melting points.
•  Soluble in polar solvents.
• Non-conductive as solids but conductive in molten form.

Metallic Lattice Characterization

•  Lattice points are occupied by cations bound by a delocalized cloud of electrons.
•  Examples include sodium (Na), potassium (K), magnesium (Mg), aluminum (Al), iron (Fe), tungsten (W), copper (Cu), silver (Ag), and gold (Au).
•  Melting points vary widely.
•  Physically insoluble (but alloy formation is possible).
•  Conduct electricity.

States of Matter Characterization

•  Properties like free path, rotation, vibration, and compressibility differ between solid, liquid, and gas states.
•  Solids have a small or negligible free path, low compressibility, fixed rotation and vibration modes, and ordered structure.
•  Liquids have a larger free path than solids, minor compressibility, and disordered structure.
• Gases have a large free path, high compressibility, rapid rotation and vibration modes, and disordered structure.

Phase Transitions and Diagrams

• Specific details of phase transitions(like sublimation)
• Important points(like the triple point) on the phase diagram are shown.
• Phase equilibrium curves(such as sublimation, melting, and vaporization).

Sublimation and Definitions

•  Sublimation is a phase transition from solid directly to gas, without forming a liquid phase.
•  Sublimation vapor pressure is the pressure of the vapor in equilibrium with the solid.
•  Sublimation heat is greater than the heat of evaporation (due to needing to overcome the heat of fusion).

Partial Pressure and Dalton's Law

•  Partial pressure is the hypothetical pressure a component in a gas mixture would exert if it were alone in the given volume and temperature.
•  Dalton's law states that the total pressure of a gas mixture is the sum of the partial pressures of its components.

Amagat's Rule

•  Amagat's rule: The total volume of a gas mixture is the sum of the partial volumes of its components.

Vapor Pressure Definition

•  Vapor pressure (or vapor tension) is the pressure of a vapor in equilibrium with its condensed phase (either solid or liquid) at a given temperature.

Vapour Definitions

• Vapor is the gas phase below the critical temperature.
• Can be condensed by increasing temperature or decreasing pressure.

Critical Temperature and Pressure

• Critical temperature: Temperature above which a substance cannot be liquefied, regardless of pressure.
• Critical pressure: Pressure required to liquefy a substance at its critical temperature.

Triple Point Definition

• The triple point is a specific set of temperature and pressure where three phases of a substance (solid, liquid, and gas) are in equilibrium.

Avogadro's Rule

• Different ideal gases at the same temperature and pressure contain the same number of molecules.

Temperature Dependence of Melting

• Pure compounds maintain a constant temperature during melting. 

Pressure Changes with Volume and Temperature

• changes in pressure during the reduction of volume at constant temperature. This is dependent on if the gas is an ideal gas or not

Freezing Point Depression

• The decrease in freezing point of a solvent when a solute is added. The depression is determined by the molar concentration of the solute.

Dilute Solution Definition

• A dilute solution is one in which the laws of dilute solutions apply.  

Molecular Mass Determination

• Molar mass can be calculated using freezing point depression, provided the depression and other relevant values are known.

Boiling Point Elevation/Depression

• Boiling point elevation/depression are related to the addition of a non-volatile solute to a solvent.
• Boiling Point Elevation/depression is related to the vapor pressure of the solvent and solute.

Osmotic Pressure Dependence

• Osmotic pressure depends on molar concentration and temperature. 

Isotonic Solutions

• An isotonic solution is one where the osmotic pressure of the solution is equal to the osmotic pressure inside cells.

Binary Mixture Vapor-Liquid Composition

• The more volatile component has a higher concentration in the vapor phase than in the liquid phase.

Boiling Temperature/Point Definitions

• Boiling temperature is reached when the vapor pressure of a liquid equals the external pressure.
• Normal boiling point is the boiling temperature at standard atmospheric pressure.

Boiling Point Depression

• If a non-volatile solute is added to the solvent, the boiling point will usually increase.

Azeotropic Composition

• The azeotropic composition of a mixture is the concentration at which the liquid and vapor concentrations are equal (in equilibrium).

Dew Point Curve and Boiling Point Curve Definitions

•  Dew Point Curve: Vapor concentrations at a given temperature (vapor in equilibrium with liquid).
• Boiling Point Curve: Liquid concentrations at a given temperature (liquid in equilibrium with vapor).

Acid-Base Definitions (Arrhenius, Bronsted, Lewis)

•  Arrhenius: Acids produce H⁺ ions, bases produce OH⁻ ions in water.
•  Bronsted-Lowry: Acids donate protons (H⁺), bases accept protons.
•  Lewis: Acids accept electron pairs, bases donate electron pairs.

Acid-Base Indicators

• An acid-base indicator changes color over a particular pH range. 

pH Concept

•  pH is calculated as the negative logarithm of the hydrogen-ion concentration ([H⁺]).
• pH measures the acidity (or alkalinity) of a solution.

pH for NaOH Solution

• pH is high for basic solutions like NaOH. For example, for a .01 mol/L solution of NaOH, the pH is approximately 12. 

pH for HCl Solution

• pH is low for acidic solutions like HCl. For example, for a .01 mol/L solution of HCl, the pH is approximately 2. 

Buffer Capacity Definition

• Buffer capacity is the amount of strong acid/base needed to change the pH of a buffer by one unit.

Buffer pH Calculation

• Calculations to determine pH of specific buffer solutions when given necessary components.

Standard Hydrogen Electrode (SHE) Definition

• A standard electrode used as a reference in electrochemistry, consisting of platinum electrode immersed in pH = 0 solution saturated with hydrogen gas at 1 atm.

Anode and Cathode

• Anode: Oxidation takes place.
• Cathode: Reduction takes place.

Electrolyte Definition

• Electrolytes are substances that conduct electricity when dissolved in a solvent or in the molten state.

Hydrogen Electrode Potential

• The potential of a hydrogen electrode measured under standard conditions—used as an electrochemical reference point. 

How to Measure Electrode Potential

• Measuring/calculating electrode potential according to given values

Redox Potential Comparison

• The oxidizing agent is associated with the more positive standard electrode potential/redox potential.

Faraday's Laws

• Mass of material that undergoes reaction is proportional to the total charge used. 

Reaction Rate Definitions

• Reaction rate is the rate of change of concentration of a reactant or product over time.

Reaction Order Definitions

• Reaction order is the sum of the exponentials of concentrations in the rate law.

Activation Energy Definition

• Activation energy is the minimum energy required for reactant molecules to undergo reaction.

Temperature Dependence of Rate Constant (Arrhenius's Law)

• Arrhenius Equation gives the logarithmic relationship between a rate constant, temperature, and activation energy.

Catalysts

• Substances that increase a reaction rate without undergoing permanent chemical change themselves. 

Atomic Number/Weight Definitions

•  Atomic number is the number of protons in the nucleus.
• Atomic weight/mass is the sum of protons and neutrons.

List of Periodic Table Elements

• List of elements by group number from the periodic table.

• VSEPR Theory Principles

• Valence Shell Electron Pair Repulsion theory which predicts the shape of molecules based on electron pair repulsion.

• Pauli Exclusion Principle

• This principle states that no two electrons in an atom can have the same set of quantum numbers.

• Hund's Rule

• Electrons fill degenerate orbitals individually first before pairing up.