Chemistry finals terms and definitions - REVIEW

Chemical Reaction

A process in which reactants react chemically and convert into products by chemical transformation. It is also a rearrangement of atoms in which some of the original bonds are broken and new bonds are formed to give different chemical structures.

Reactants

These are the starting substances.

Products

New substances that result from chemical reactions.

Chemical Equation

Shorthand way of describing a reaction.

(s)

symbol for solid in a chemical reaction

(l)

symbol for liquid in a chemical reaction.

(g)

Symbol for gases in a chemical reaction.

(aq)

Symbol for aqueous solution in a chemical reaction.

Law of Conservation of Mass

Total mass of the products of a reaction is equal to the total mass of the reactants.

Antoine Lavoisier

Established the law of conservation of mass.

Same

A balanced chemical equation has the _________ number of each type of atom on the product side and the reactant side.

Synthesis Reaction

Two or more substances combine to for a new compound.

Polymerization

The process of creating large molecules from small ones is called ___________.

Decomposition Reaction

A chemical reaction in which a single compound is broken down to produce two or more smaller compounds.

Single Displacement Reaction

One element replaces a similar element in a compound.

Double Displacement

Ions from two compounds in solution exchange places to produce two new compounds. The compounds formed is usually a precipitate that settles out of the solution.

Precipitate

It is a new solid product that comes out of a solution in a chemical reaction.

Soluble Compounds

These compounds break down when put in water.

Insoluble Compounds

These compounds do NOT break down when put in water.

Surface Area

The more ___________ that is exposed, the faster the reaction will occur.

Temperature

The higher the ________________ the faster the particles move.

Concentration

The amount of substance in a given volume.

Catalyst

Material that increases the rate of reaction by lowering activation energy.

Enzymes

Cells in your body that acts as catalysts.

Inhibitor

material used to decrease the rate of a reaction.

Exothermic

Chemical reactions that emit thermal energy when they occur.

Endothermic

Chemical reactions that absorb thermal energy when they occur.

Enthalpy

The amount of thermal energy emitted or absorbed by a chemical reaction, under conditions of a constant pressure, can be quantified with a function called ____________________.

Enthalpy of reaction

The amount of thermal energy that flows when a reaction occurs at constant pressure.

Stoichiometry

Section of chemistry that involves using relationships between reactants and/or products in a chemical reaction to determine desired quantitative data.

Stoikhein

Greek word meaning “element'“.

Metron

Greek word meaning “pressure”.

Mole

The amount of substance that contains the same number of entities .

Molar Mass

The mass per mol of its entities.

Empirical Formula

Shows the lowest number of moles and gives the relative number of atoms of each element present.

Molecular Formula

Shows the actual number of atoms of each element in a molecule of the compound.

Solution

Homogenous mixture of 2 or more substances evenly distributed throughout a single phase.

Solute

Substance that is dissolved

Solvent

Dissolving Medium

Solubility

The ability of a substance to be dissolved.

Saturation

The solubility of a solute in a solvent relative to the amount used.

Unsaturated

Contains less solute than the maximum amount of solute a solvent can design.

Saturated

Contains equal amount of solute to the maximum amount of solute a solvent can dissolve.

Supersaturated

Contains more solute than the maximum amount of solute a solvent can dissolve.

Concentration

The amount of solute dissolved in a given amount of solvent.

Dilute Solution

Has relatively low concentration.

Concentrated Solution

Has relatively high concentration.

Parts per million

The number of grams of solute in a million grams of solution. This is used when the solution is very dilute.

Molarity

The number of moles so solute per liter of solution

Molality

The number of moles so solute per kilogram of solvent.

Mixture

a substance made by combining two or more different materials in such a way that no chemical reaction occurs.

Suspension

A heterogenous mixture containing solid particles that are sufficiently large for sedimentation.

Colloid

A homogenous solution with intermediate particle size between a solution and a suspension.

Aqueous

Describes a solution in which the solvent is water.

Filtration

can be used to separate a solid from a liquid.

Evaporation

Can be used to separate a dissolved solute from a solution.

Distillation

is a method of separating chemical substances based on differences in their volatilities in a boiling liquid mixture.

Chromatography

a physical method of separation in which the components to be separated are distributed between two phases.

Polar solvents

Dissolve polar compounds

Nonpolar solvents

Dissolve nonpolar compounds

Miscible

Indicates that liquids will dissolve each other

Immiscible

Indicates that liquids will not dissolve appreciably each other.

Conductivity

is a measure of water’s ability to conduct electrical current.

Electrical Conductivity

is a measure of a material’s ability to conduct an electric current.

Electrolytes

are substances that become ions in solution and acquire the capacity to conduct electricity.

Non electrolyte

a substance that does not dissociate into ions and so in a solution it is a nonconductor of electricity.

Dissociation

A process in which a compound separated intro fragments.

Hydration

The process by which water molecules surround each ions as it moves into solution.

Polarity

Indicates that a solute will dissolve best in a solvent that has a similar _______________ to itself.

Colligative Properties

These are properties that depend upon the concentration of solute molecules or ions, but not upon the identity if the solute.

Emulsion

is a mixture of two immiscible substances. One substance is dispersed in the other.

Emulsification

is the process which emulsions are prepared.

Acid

is a solution with an excess of H+ ions. These substances taste sour.

Base

A solution that has an excess of OH- ions. These substances taste bitter.

Alkali

Another word for bases.

Neutralization

A reaction between an acid an a base.

pH

measures how acidic or basic a solution is.

Acidic Solutions

have pH values below 7

Neutral solution

a solution with a pH of 7

Basic Solution

a solution with pH values above 7.

Force

Holds particles together.

Intermolecular force

the attractions between molecules

Intramolecular force

is the force that keep a molecule together.

Kinetic Energy

Particles can move apart only if they have enough _____________ to overcome this force of attraction.

Atmospheric pressure

The gas molecules in the atmosphere are pulled toward due to gravity exerting pressure.

Barometer

measures atmospheric pressure.

Standard Atmospheric Pressure

SAP

Standard Temperature and Pressure

STP

Boyle’s Law

The pressure and volume of gas are inversely proportional ( as one increases the other decreases.)

Charles’ Law

The volume and absolute temperature of a gas are directly proportional.

Gay-Lussac’s Law

The pressure and absolute temperature (K) of a gas are directly proportional ( as temperature rises, so does pressure.)

22.4

constant value of mol in gases.