Physical Science Chapter 19 terms

By Akaysha B

Balanced chemical equation

a chemical equation with the same number of atoms of each element on both sides of the arrow.

chemical equation

a way to describe a chemical reaction using chemical formulas and other symbols

chemical reaction

a change in which one or more substances are converted into new substances

coefficient

represent the number of units of each substance taking part in a reaction

molar mass

the mass in grams of one mole of a substance

mole

the amount of substance that contains 6.02 × 10²³ particles of that substance.

products

the new substances produced after a chemical reaction

reactants

the starting substances that react in a chemical reaction

combustion reaction

occurs when a substance reacts with oxygen to produce energy in the form of heat and light.

decomposition reaction

occurs when one substance breaks down or decomposes into two or more substances (AB → A + B)

double displacement reaction

occurs when the positive ion of one compound replaces the positive ion of the other to form two new compounds (AB + CD → AD + CB)

oxidation

the loss of electrons

precipitate

an insoluble compound that comes out of solution during a double displacement reaction

reduction

the gain of electrons

single displacement reaction

the chemical reaction in which one element replaces another element in a compound (A + BC → AC + B)

synthesis reaction

two or more substances combine to form another substance (A + B → AB)

endergonic reaction

when a chemical reaction requires more energy to break bonds than is released when new ones are formed

endothermic reaction

when the energy needed to keep a reaction going is in the form of thermal energy

exergonic reaction

a chemical reaction that releases energy

exothermic reaction

when the energy given off in a reaction is primarily in the form of thermal energy

catalyst

a substance that speeds up a chemical reaction without being permanently changed itself

collision model

states that atoms, ions, and molecules must collide in order to react

equilibrium

a state in which forward and reverse reactions or processes proceed at equal rates

inhibitor

a substance used to slow down the rate of chemical reactions or prevent a reaction from happening at all.

Le Châtelier’s principle

states that if a stress is applied to a system at equilibrium, the equilibrium shifts in the direction that opposes the stress

reaction rate

the rate at which reactants change into products

reversible reaction

a reaction that can occur in both the forward and reverse directions