Comprehensive Chemistry: Equations, States, and Reactions

What is a chemical reaction?

The process where reactants are transformed into products.

What is a chemical equation?

Concise representations of chemical reactions.

What is the Law of Conservation of Mass?

In a chemical reaction, mass is neither created nor destroyed.

What are coefficients in a chemical equation?

Coefficients determine the number of representative particles of a substance and are used to balance a chemical equation.

What are the 4 symbols used for states of matter in a chemical equation?

(s) - solid, (g) - gas, (l) - liquid, (aq) - aqueous.

What is a synthesis reaction?

2 or more elements combine to form a compound.

What is a decomposition reaction?

A compound breaks down into 2 or more simpler substances.

What is a single replacement reaction?

One element replaces or switches with another element in a compound.

What is a double replacement reaction?

The exchange of cations between two ionic compounds.

What is a combustion reaction?

Hydrocarbons react with oxygen to produce carbon dioxide and water vapor.

What is a precipitation reaction?

A type of double replacement reaction that produces a solid when 2 aqueous solutions are mixed.

What is an acid-base reaction?

Produces water and a salt when H+ and OH- combine.

What is oxidation in a redox reaction?

The loss of electrons.

What is reduction in a redox reaction?

The gain of electrons.

When is a solubility chart used?

To predict if the products of a double replacement reaction will be aqueous or solid.

What is a spectator ion?

Ions present before and after a reaction that are not involved in the formation of the solid.

What is a complete ionic equation?

Separates all aqueous compounds into their corresponding cations and anions.

What is a net ionic equation?

Shows only the ions that form the precipitate, excluding spectator ions.

What is stoichiometry?

The study of mathematical relationships in chemical reactions.

What is a mole ratio?

A conversion factor between any 2 species in a chemical reaction.

What is a limiting reagent?

The reagent that runs out first and stops the reaction.

What is excess reagent?

The reagent that is not completely used up in the reaction.

What is theoretical yield?

The maximum amount of product that can be formed.

What is actual yield?

The amount of product that forms when the reaction is carried out.

What is percent yield?

The ratio of actual yield to theoretical yield.

What is atmospheric pressure?

The force exerted by air due to gravity.

What is standard atmospheric pressure?

Air pressure at sea level (1 atm, 760 mmHg, 101.3 kPa).

What is boiling point?

The temperature at which vapor pressure equals atmospheric pressure.

What is normal boiling point?

The boiling point at 1 atm pressure.

What is melting point?

The temperature at which a solid changes into a liquid.

What is freezing point?

The temperature at which a liquid changes into a solid.

What is evaporation?

The transition of particles from liquid to gas at a temperature below the boiling point.

What is vapor pressure?

The pressure exerted by gas particles above a liquid.

What does it mean if a solid has a crystal structure?

Particles are arranged in an orderly, repeating, 3-D pattern.

What is a unit cell?

The smallest group of particles within a crystal that retains the geometric shape.

What are allotropes?

Different molecular structures of the same element.

What is an amorphous solid?

A solid lacking an ordered internal structure.

What are the three assumptions of the kinetic theory of gases?

Gas particles have negligible volume, are in constant motion, and have elastic collisions.

How can the pressure of a gas be increased?

By increasing the number of particles, decreasing volume, or increasing temperature.

What is the relationship between kinetic energy and temperature?

Temperature is a measure of the average kinetic energy of particles.

What happens to atmospheric pressure as you change elevation?

It decreases with higher elevation and increases with lower elevation.

How does evaporation differ from boiling?

Evaporation occurs below boiling point without bubbles; boiling occurs at boiling point with bubbles.

How is vapor pressure affected by temperature?

Vapor pressure increases as temperature increases.

What happens to the boiling point of a liquid as elevation changes?

It decreases above sea level and increases below sea level.

What are the six phase changes?

Melting, freezing, vaporizing, condensing, sublimation, deposition.

What is a phase diagram?

Shows the relationship between temperature and pressure and their effects on phases of matter.

What is a critical point?

Where liquid and gas phases are indistinguishable.

What is a triple point?

Where solid, liquid, and gas phases all exist at equilibrium.

What do the lines represent on a phase diagram?

The points at which a phase change occurs.