Chem H Final Study Guide

Matter

Anything that takes up space and has mass.

Mass

The amount of matter in an object, measured in grams or kilograms.

Solid

A state of matter with definite shape and definite volume.

Liquid

A state of matter with indefinite shape and definite volume.

Gas

A state of matter with indefinite shape and indefinite volume.

Plasma

A high-temperature state of matter where particles are stripped away from their atoms.

Physical Properties

Observable properties that can be determined without destroying the object, such as color, shape, and density.

Chemical Properties

Properties that indicate how a substance reacts with other substances, such as the ability of iron to rust.

Extensive Properties

Properties that depend on the amount of matter present, such as volume and weight.

Intensive Properties

Properties that do not depend on the amount of matter, such as color and temperature.

Physical Changes

Changes in matter that do not alter the composition of the substance, such as melting or dissolving.

Chemical Changes

Changes that involve a transformation of one substance into another, producing new substances.

Substances

Matter with the same composition throughout, which can be either elements or compounds.

Mixtures

Combinations of two or more substances that retain their individual properties.

Elements

The simplest forms of matter that cannot be broken down by chemical means.

Compounds

Chemical combinations of two or more elements joined in fixed proportions.

Homogeneous Mixtures

Mixtures with a uniform composition throughout, such as Kool-Aid or air.

Heterogeneous Mixtures

Mixtures where individual substances are not uniformly distributed and can be distinguished, such as trail mix.

Reactants

The starting substances in a chemical reaction.

Products

The substances formed as a result of a chemical reaction.

Endothermic Reaction

A reaction that absorbs heat from the surroundings, resulting in a cooler feeling.

Exothermic Reaction

A reaction that releases heat to the surroundings, resulting in a warmer feeling.

Law of Conservation of Mass

A principle stating that mass cannot be created or destroyed in a chemical reaction.

Solution

A homogeneous mixture composed of solute and solvent.

Solute

The substance being dissolved in a solution.

Solvent

The substance that dissolves the solute in a solution.

Molar Volume

The volume occupied by one mole of a substance at standard temperature and pressure (STP) is 22.4 L.

Significant Figures

Digits in a measurement that carry meaningful information about its precision.

Avogadro’s Number

The number of particles in one mole of a substance, approximately 6.022 x 10²³.

Chemical Equation

A representation of a chemical reaction using symbols and formulas for the reactants and products.

Combustion Reaction

A reaction between a substance and oxygen producing heat and light, often resulting in a hydrocarbon reacting with oxygen to form carbon dioxide and water.

Hydrate

A compound that contains water molecules within its structure.

Melting

Solid to Liquid at 0 degrees

Freezing

Liquid to Solid at 0 degrees

Boiling

Liquid to Gas at 100 degrees

Condensing

Gas to Liquid at 100 degrees

Deposition

Gas to Solid without becoming liquid.

Sublimation

Solid to Gas without becoming liquid.

Alloy

A substance created when two or more metals are combined together.

Metals

Shiny luster, ductile, malleable, conduct heat and electricity well, usually solids at room temperature.

Nonmetals

Does not conduct electricity and heat well, brittle, lack luster, many are gaseous at room temperature.

Metalloids

Have properties of both metals and nonmetals; semiconductors, better than non metals but worse than metals.

Qualitative

Not measurable, described with words.

Quantitative

Measurable, described with numbers.

Mass

The quantity of matter in an object, typically measured in kilograms or grams.

Weight

The force exerted on an object due to gravity, typically measured in newtons or pounds.

Density

The mass of an object divided by its volume, typically measured in grams per cubic centimeter (g/cm³) or kilograms per cubic meter (kg/m³).

Accuracy

The degree to which a measurement adheres to the true value of the quantity being measured.

Precision

The degree to which repeated measurements under unchanged conditions show the same results, indicating consistency or reliability in measurements.

Isotopes

Atoms of the same element with different numbers of neutrons, resulting in varying atomic masses.

Mass Number

The total number of protons and neutrons in an atomic nucleus, representing the atomic mass of an isotope.

Atomic Mass

The weighted average mass of an element's isotopes, reflecting their relative abundances.

Periods

Horizontal rows in the periodic table that group elements based on increasing atomic number and similar electron shell configurations.

Groups

Vertical columns in the periodic table that group elements with similar properties and valency.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Mole Concept

One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). Is used to convert between mass and number of particles.

Molar Mass

The ratio between the mass and the amount of substance of any sample of said compound; measured in grams.

STP Conditions

Standard temperature and pressure conditions for gases, defined as 0 degrees Celsius and 1 atmosphere pressure; associated with 22.4 L.

Reactants

Substances that undergo a chemical reaction to form products.

Products

Substances that result from a chemical reaction, generated from reactants.

Precipitate

An insoluble solid that forms during a chemical reaction when two solutions react.

Catalyst

A substance that increases the rate of a chemical reaction without being consumed in the process.

Inhibitor

A substance that decreases the rate of a chemical reaction, often by interfering with the catalyst or reactants.

Synthesis

Reaction in which two or more substances combine to form only one product.

Decomposition

Reaction in which a single compound breaks down into two or more products.

Single Replacement

Reaction in which one element is replaced by another in a compound, resulting in two products.

Double Replacement

Reaction where two compounds exchange components, resulting in two new compounds.

Combustion

Burning or reaction with oxygen producing heat.

Complete Combustion

Occurs when a hydrocarbon burns in sufficient oxygen, producing only carbon dioxide and water.

Incomplete Combustion

Occurs when there is not enough oxygen for a hydrocarbon to burn completely, resulting in the production of carbon monoxide and water.

Heat

Energy transfer between samples of matter because of a difference in their temperatures (hot flows to cold until equilibrium is reached).

Temperature

A measure of the average kinetic energy of the particles in a sample of matter (greater kinetic energy, higher temperature).

Specific Heat Capacity

The amount of energy/heat required to raise the temperature of one gram of a substance by one degree Celsius.