1[AP Chem U4 Vocab 001] What is a chemical reaction?
A process in which atoms are rearranged as chemical bonds break and form, producing substances with different chemical identities.
2[AP Chem U4 Vocab 002] What is a reactant?
A substance consumed or transformed during a chemical reaction, written on the left side of a chemical equation.
3[AP Chem U4 Vocab 003] What is a product?
A substance formed by a chemical reaction, written on the right side of a chemical equation.
4[AP Chem U4 Vocab 004] What is a chemical equation?
A symbolic representation of a chemical reaction showing reactants, products, and their relative stoichiometric amounts.
5[AP Chem U4 Vocab 005] What is a balanced chemical equation?
An equation with equal numbers of atoms of each element on both sides, consistent with conservation of matter.
6[AP Chem U4 Vocab 006] What is a stoichiometric coefficient?
A number placed before a chemical formula indicating the relative number of particles or moles involved in a balanced reaction.
7[AP Chem U4 Vocab 007] What is a subscript in a chemical formula?
A number indicating how many atoms of an element occur in a formula unit or molecule; changing it changes the chemical formula.
8[AP Chem U4 Vocab 008] What is the law of conservation of mass?
In a closed system, total mass remains constant during a chemical reaction because atoms are rearranged rather than created or destroyed.
9[AP Chem U4 Vocab 009] What is a complete ionic equation?
An equation showing dissolved strong electrolytes as their constituent ions while retaining substances that do not dissociate completely in ionic form.
10[AP Chem U4 Vocab 010] What is a net ionic equation?
An equation showing only the species that participate in the chemical change, with spectator ions removed.
11[AP Chem U4 Vocab 011] What is a spectator ion?
An ion that appears unchanged on both sides of a complete ionic equation and is omitted from the net ionic equation.
12[AP Chem U4 Vocab 012] What is an electrolyte?
A substance that produces mobile ions when dissolved in water or melted, allowing the resulting solution or liquid to conduct electricity.
13[AP Chem U4 Vocab 013] What is a strong electrolyte?
A substance that produces ions essentially completely in aqueous solution, such as a soluble ionic salt or strong acid.
14[AP Chem U4 Vocab 014] What is a weak electrolyte?
A substance that produces relatively few ions in aqueous solution because ionization is incomplete, such as a weak acid.
15[AP Chem U4 Vocab 015] What is a nonelectrolyte?
A substance that dissolves without producing significant concentrations of ions and therefore contributes little to electrical conductivity.
16[AP Chem U4 Vocab 016] What is a precipitation reaction?
A reaction in which dissolved species combine to form an insoluble solid.
17[AP Chem U4 Vocab 017] What is a precipitate?
An insoluble solid formed from substances initially present in solution.
18[AP Chem U4 Vocab 018] What does aqueous, (aq), indicate?
A substance is dissolved in water; the notation alone does not establish whether the dissolved substance is ionized.
19[AP Chem U4 Vocab 019] What does the state symbol (s) indicate?
The substance is in the solid state.
20[AP Chem U4 Vocab 020] What does the state symbol (l) indicate?
The substance is in the liquid state.
21[AP Chem U4 Vocab 021] What does the state symbol (g) indicate?
The substance is in the gaseous state.
22[AP Chem U4 Vocab 022] What is a physical change?
A change in physical form or state without changing the chemical identity of the substance.
23[AP Chem U4 Vocab 023] What is a chemical change?
A process that changes chemical identities through rearrangement of atoms and chemical bonds.
24[AP Chem U4 Vocab 024] What is stoichiometry?
The quantitative study of relationships among reactants and products using the coefficients of balanced chemical equations.
25[AP Chem U4 Vocab 025] What is a mole ratio?
The ratio of stoichiometric coefficients that relates amounts of two substances in a balanced chemical equation.
26[AP Chem U4 Vocab 026] What is a limiting reactant?
The reactant consumed first according to the reaction stoichiometry, determining the maximum amount of product that can form.
27[AP Chem U4 Vocab 027] What is an excess reactant?
A reactant present in more than the stoichiometric amount required to consume the limiting reactant.
28[AP Chem U4 Vocab 028] What is theoretical yield?
The maximum amount of product predicted from the limiting reactant, assuming complete reaction and no product losses.
29[AP Chem U4 Vocab 029] What is actual yield?
The amount of product actually obtained in an experiment.
30[AP Chem U4 Vocab 030] What is percent yield?
The actual yield divided by the theoretical yield, multiplied by 100%.
31[AP Chem U4 Vocab 031] What is a titration?
An analytical procedure in which a solution of known concentration reacts with an analyte to determine an unknown quantity, commonly concentration.
32[AP Chem U4 Vocab 032] What is a titrant?
The solution delivered during a titration, usually from a buret, to react with the analyte.
33[AP Chem U4 Vocab 033] What is an analyte?
The substance being analyzed, whose amount or concentration is being determined.
34[AP Chem U4 Vocab 034] What is the equivalence point of a titration?
The point at which the added titrant and analyte have reacted in the exact stoichiometric ratio specified by the balanced equation.
35[AP Chem U4 Vocab 035] What is a titration endpoint?
The experimentally observed signal, such as an indicator color change, used to estimate the equivalence point.
36[AP Chem U4 Vocab 036] What is an acid in the Brønsted–Lowry model?
A species that donates a proton, H+, to another species.
37[AP Chem U4 Vocab 037] What is a base in the Brønsted–Lowry model?
A species that accepts a proton, H+, from another species.
38[AP Chem U4 Vocab 038] What is an acid–base reaction in the Brønsted–Lowry model?
A reaction involving transfer of a proton from an acid to a base.
39[AP Chem U4 Vocab 039] What is a conjugate acid–base pair?
Two species that differ by exactly one proton, with the acid containing one more H+ than its conjugate base.
40[AP Chem U4 Vocab 040] What is an oxidation–reduction reaction?
A chemical reaction involving electron transfer, reflected in changes in oxidation numbers.
41[AP Chem U4 Vocab 041] What is oxidation?
Loss of electrons by a species, corresponding to an increase in oxidation number.
42[AP Chem U4 Vocab 042] What is reduction?
Gain of electrons by a species, corresponding to a decrease in oxidation number.
43[AP Chem U4 Vocab 043] What is an oxidizing agent?
A species that causes another species to be oxidized by accepting electrons; the oxidizing agent is itself reduced.
44[AP Chem U4 Vocab 044] What is a reducing agent?
A species that causes another species to be reduced by donating electrons; the reducing agent is itself oxidized.
45[AP Chem U4 Vocab 045] What is an oxidation number?
A formal charge assigned to an atom using electron-accounting rules to track oxidation and reduction in chemical reactions.