Thermochemistry and Chemical Bonding Fundamentals
Thermochemistry and Chemical Bonding
Key Concepts in Thermochemistry
- Vaporization Heat: The amount of heat needed to convert 1 mol of a liquid substance to gas.
- Melting Point: A constant temperature where a balance exists between the liquid and solid phases.
- Boiling Point: A constant temperature where a balance exists between the gas and liquid phases.
- Freezing Point: A constant temperature where equilibrium exists between the liquid and solid phases.
- Heat of Reaction (Enthalpy): The amount of heat absorbed
Types of Solids and Chemical Bonds
Types of Solids and Their Properties
This table summarizes the properties of different types of solids:
| Type of Solid | Example Substance | Particles in the Crystal | Links Between Particles | Properties |
|---|---|---|---|---|
| Molecular | Simple substances or compounds of nonmetallic elements | Molecules (multimolecular structure) | Intermolecular forces | Low melting and boiling temperatures, not soluble in polar solvents. If polar, they may conduct in solution. If nonpolar, they will not conduct. |
| Giant Covalent | Diamond | Atoms (giant structure) | Covalent |
Nuclear Reactions: Types and Applications
1. Alpha Particle (?) Reaction
In 1919, Rutherford observed the first nuclear reaction. In his experiment, he bombarded nitrogen (N) gas with alpha (?) particles from a radioactive source. The products obtained were oxygen, hydrogen, and Q. Q represents the energy released or absorbed during the nuclear reaction.
- If Q is positive, energy is released, and the reaction is exoenergetic.
- If Q is negative, energy is absorbed, and the reaction is endoenergetic.
Q is also known as the decay energy and equals
Read MoreThermodynamics and Chemical Kinetics: A Concise Review
Thermodynamics and Chemical Kinetics
Power: The ability of a body to produce work or heat, generating chemical reactions. Energy is exchanged between atoms, ions, and molecules. Each substance transfers energy through heat or work mechanisms. Work is defined as force applied over a distance (W = -PΔV). Heat and thermal energy are transferred naturally between bodies within thermodynamic systems.
- Adiabatic Wall: Prevents heat exchange (thermally insulated) between a system and its surroundings.
- Diathermic
Understanding Matter: Properties, Changes, and Reactions
Chemistry Basics
► Chemistry: The study of the properties and transformations of matter. ► Matter: Anything that has mass and occupies space – things you can see, touch, taste, or smell. ► Property: A characteristic that can be used to describe a substance. Substances have both physical and chemical properties. ► Transformations: A change in the properties of matter with time. There are physical changes and chemical changes.
Properties of Matter
Matter has both physical and chemical properties.
Read MoreSolubility, States of Matter, and Gas Laws
Solubility and Its Characteristics
The solubility of a pure substance in a given solvent at a specific temperature is one of its characteristic properties.
Defining Solubility
The solubility of a solute at a given temperature and in a given solvent is the maximum amount of solute that can dissolve in 100g of the solvent at that temperature.
Solubility of Gases
When you raise the temperature of a solution containing a dissolved gas, the solubility decreases. The solubility of a gas in a liquid increases
Read More