Chemistry Lecture Notes: Matter and Measurement

Flashcards covering key concepts from the chemistry lecture on matter, measurement, and problem solving.

Macroscopic vs. Microscopic View

Chemistry bridges the gap between the observable world (macroscopic) and atomic/molecular behavior (microscopic).

Compounds

Substances with a definite composition, where the relative number of atoms for each element is identical in every sample (Law of Constant Composition).

Elements

Pure substances that cannot be decomposed into simpler substances.

Mixtures

Combination of two or more substances that can be separated via physical means.

Intensive Properties

Properties that do not depend on the amount of substance, e.g., density and temperature.

Extensive Properties

Properties that depend on the amount of substance, e.g., mass and volume.

Precision

How close measurements are to each other, indicating reproducibility.

Accuracy

How close a measurement is to the true value.

Dimensional Analysis

A method of converting units by treating conversion factors like algebraic quantities.

Atomic Mass Unit (amu)

Defined as 1/12th the mass of one Carbon-12 atom.

Atomic Weight

A weighted average of the masses of all naturally occurring isotopes of an element.

Ionic Compounds

Compounds formed from metals and nonmetals, with Roman numerals used for metals with multiple charges.

Molecular Compounds

Compounds made of nonmetals, where Greek prefixes indicate the number of atoms.

Binary Acids

Acids formed from hydrogen and one other element, using the prefix hydro- and suffix -ic.

The Mole

A unit representing 6.022×10^23 particles of a substance, with a mass in grams equal to its formula weight.

Molecular Weight

The sum of atomic weights for a molecule.

Percent Composition

The mass of an element in one mole of a compound divided by the molar mass of the compound, multiplied by 100.

Empirical Formula

The simplest whole-number ratio of atoms in a compound.

Molecular Formula

The actual number of atoms of each element in a compound.

Limiting Reactant

The reactant that produces the smallest amount of product in a chemical reaction.

Percent Yield

Calculated as (Actual Yield/Theoretical Yield)×100, indicating efficiency of a reaction.