Chemistry Lecture Review

Flashcards created to help review key chemistry concepts discussed during the lecture.

Thermal Chemistry

The branch of chemistry that deals with the relationship between heat and chemical reactions, focusing on energy transfer that occurs in these processes.

Allotropes

Different forms of the same element in the same physical state, such as graphite and diamond for carbon, demonstrating how atomic arrangement affects properties.

Polymorphic Materials

Materials that can exist in multiple structural forms, like chocolate which can solidify in different crystal structures, affecting its texture and melting behavior.

Refractive Index

A measure of how much light is bent or refracted when entering a material; a higher refractive index indicates a greater bending effect, as seen in diamonds.

Conductivity

The ability of a material to conduct electricity, which is typically higher in metals due to the presence of free electrons, compared to semiconductors and insulators.

Doping

The process of adding impurities to a semiconductor to change its electrical properties; this is crucial for creating p-type and n-type semiconductors for electronic devices.

Henry's Law

A gas law stating that the amount of gas dissolved in a liquid is proportional to the pressure of the gas above the liquid, often used in calculations related to gas solubility.

Molarity

The number of moles of solute per liter of solution, commonly used as a concentration unit in chemistry, symbolized as M.

Molality

The number of moles of solute per kilogram of solvent, represented as m; useful in scenarios where temperature changes affect volume.

Colligative Properties

Properties of solutions that depend on the number of solute particles, such as boiling point elevation, freezing point depression, and osmotic pressure, rather than the identity of the solute.

Ideal Solutions

A solution that obeys Raoult's Law, where the interactions between solvent and solute molecules are similar, resulting in predictable behavior of vapor pressure.

Mass Percentage

The mass of a solute divided by the total mass of the solution, expressed as a percentage; helps in understanding the concentration of components in a mixture.

Mole Ratio

The ratio of the number of moles of one substance to the number of moles of another substance in a chemical reaction; critical for stoichiometric calculations.

Normality

A concentration unit equivalent to the number of equivalents of solute per liter of solution; often used in acid-base chemistry and redox reactions to express the capacity to react.