Solubility, 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 when more pressure is exerted.
Supersaturated Solutions
A supersaturated solution contains a greater amount of solute than that corresponding to its saturation point.
Oil and Its Formation
Oil, a fossil fuel, is a blackish, oily substance found in certain rocks. Conditions favoring oil formation include:
- Shallow seas rich in nutrients
- Sediment contributions from rivers
- Minimal or weak bottom water movement
Oil is a mixture of various hydrocarbons and other substances. It typically exists in a reservoir in three phases:
- Solid phase: Asphalt
- Liquid phase: Oil
- Gas phase: Natural gas
Characteristics of Matter’s States
Gases
- Status: Constant mass, variable volume, variable shape, and can flow.
Liquids
- Status: Constant mass, constant volume, variable shape, and can flow.
Solids
- Status: Constant mass, constant volume, fixed shape, does not flow.
Gas, Vapor, and Atmosphere
Gas: Substances in a gaseous state at standard pressure and temperature.
Vapor: A gas that originates from a substance that, at standard pressure and temperature, is a solid or liquid (e.g., water vapor or iodine vapor).
Atmosphere: A gaseous layer composed of a mixture of gases.
Atmospheric pressure: The pressure exerted by the atmosphere due to its weight on the surface of bodies in contact with it.
Expansion: The increase in volume a body experiences as its temperature increases.
Gas Laws
Boyle’s Law
At constant temperature, the volume occupied by a given mass of gas is inversely proportional to pressure.
Formula: P1V1 = P2V2
Gay-Lussac’s First Law
If the gas pressure remains constant, the volume of a fixed mass of gas is directly proportional to its absolute temperature.
Formula: V1/T1 = V2/T2
Gay-Lussac’s Second Law
If the volume of a gas remains constant, the pressure of a fixed mass of gas is directly proportional to its absolute temperature.
Formula: P1/T1 = P2/T2
Combined Gas Law
For a given mass of gas, when conditions of pressure, volume, and temperature are modified.
Formula: P1V1/T1 = P2V2/T2
Models and Kinetic Theory
Model: An abstraction of reality that allows for a simplified representation of it.
Kinetic Model of Gases
- Heating a Gas: When a gas is heated, its temperature increases. Gas particles gain energy and move faster.
- Gas Pressure: When a gas is contained, particles constantly move and collide with the container walls.
- Gas Expansion: Gas particles can be variably distanced. When a gas expands, the particles separate.
Kinetic Theory of Matter
- Matter is composed of tiny, invisible particles.
- These particles are in constant, random motion.
Phase Transitions
Graph of Change in State: A graphical representation of temperature versus time.
Melting Point: The temperature at which a substance changes from solid to liquid, and vice versa.
Boiling Point: The temperature at which a substance changes from liquid to gaseous state, and vice versa.
Changes of State
- Solid to Liquid: Fusion (Melting)
- Liquid to Gas: Vaporization/Boiling
- Liquid to Gas: Vaporization/Evaporation
- Solid to Gas: Sublimation
Evaporation
Evaporation occurs when vaporization takes place at any temperature and only at the free surface of the liquid.