CHEM 10 Mid Term

Flashcards pertaining to the halfway point of CHEM 10 - Foundations of Chemical Principles.

Percent Abundance

The percentage of each isotope of an element found in nature, compared to the total amount of that element.

Isotope

Atoms of the same element with a unique number of neutrons.

Unit for atomic mass

g/mol or atomic mass unit (amu)

Equation for solving percent abundance

A = m_{1}x + m_{2}(1-x)

To balance a chemical equation is to…

…adjust the coefficients so that the number of each type of atom is the same on both sides of the equation.

Equilibrium Constant

A numerical value that expresses the ratio of product concentrations to reactant concentrations at equilibrium, each raised to their stoichiometric coefficients.

Notation for Equilibrium Constant

K_{eq}

Equilibrium in a reaction occurs when…

…the rate of the forward reaction (reactant-to-product) is equal to the rate of the reverse reaction (product-to-reactant). At this point, the concentrations of the reactants and products remain constant.

Equilibrium constant is equal to the ratio of the ___, divided by the the ratio of the ___.

products, reactants

Concentration (of a particular element or compound) is measured in…

…moles per liter (mol/L) or simply M.

A reaction is considered to be “product favored” when K_eq is…

> 1

A reaction considered to be “product favored” will proceed to the…

…right

If a reaction is “product favored” it has more…

…products than reactants

A reaction is considered to be “reactant favored” when K_eq is

< 1

A reaction considered to be “reactant favored” will proceed to the…

…left

If a reaction is “reactant favored” it will have…

…more reactants than products.

Avogadro’s number is

The number of particles (atoms, ions, molecules) in one mole of a substance. It’s value is 6.022 × 10²³.

Le Chatelier’s principle states that when a reaction at equilibrium is disturbed by a change in ___, ___, or ___, the system shifts to counteract that change.

concentration, pressure, temperature

In ___ reactions, heat acts like a reactant, shifting equilibrium toward products.

endothermic

In ___ reactions, heat acts like a product, shifting equilibrium toward reactants.

exothermic

If heat is absorbed in a reaction, the reaction can be classified as…

…endothermic

If heat is released in a reaction, the reaction can be classified as…

…exothermic

A lower K_eq value indicates ___ solubility

lower

A higher K_eq value indicates ___ solubility

higher

In an acid-base neutralization reaction, the acid ___ a Hydrogen anion.

donates

In an acid-base neutralization reaction, the base ___ a Hydrogen anion.

accepts

The conjugate pair of an acid is the…

…conjugate base

The conjugate pair of a base is the…

…conjugate acid

An acid-base neutralization reaction is a type of ___ reaction.

Double Displacement (Precipitation)

The general pattern of Double Displacement (Precipitation) reactions is…

AB + CD → AD + CB

Net ionic equations show…

…only the species that undergo a chemical change.

Species that do not change charge in a double-displacement (precipitation) reaction are called ___ ___ and are not included in net ionic equations.

spectator ions

Chemical species included in Chemical Equilibrium equations include…

aqueous (aq) and gaseous (g)

A substance/ion is considered to be ___ if it can both accept and donate an H+ ion (i.e. it can be either an acid or a base).

Amphiprotic

Amphiprotic substances/ions must have…

An H anion and another atom with a negative charge, or a lone pair

Equation for the autoionization of water.

2H2O(l) → H3O+(aq) + OH-(aq)

The pH of a solution is based upon the concentration of ___ ions.

H+ (or similarly, H3O+)

The pOH of a solution is based upon the concentration of ___ ions.

OH-

pH of a solution is calculated by the equation…

-log[H+] or -log[H3O+]

pOH of a solution is calculated by the equation…

14 - (-log[H+])

The relationship between pOH and pH is…

pOH = 14 - pH

In an oxidation-reduction reaction, one species is ___, while the other is ___.

oxidized, reduced

An ___ ___ is a number that represents the charge an atom would have if all the electrons in a compound were assigned to the more electronegative element.

oxidation number

An oxidation-reduction reaction is also called a ___ reaction.

redox

Oxidation number for uncombined elements by themselves 

0

Oxidation number of monatomic ions

[charge]

Oxidation number of Oxygen

-2 (not true for peroxides)

Oxidation number for peroxides (such as H2O2)

-1

Oxidation number for Hydrogen when bonded to non-metals

+1

Oxidation number for Hydrogen when bonded to metals

-1

Oxidation number for Fluorine

-1

A compound’s overall charge is…

…the sum of all of it’s oxidation numbers

When an ion loses electrons in a redox reaction, it is ___ and is the ___ agent.

oxidized, reducing

When an ion gains electrons in a redox reaction, it is ___ and is the ___ agent.

reduced, oxidizing

l value for the s-orbital

0

l value for the p-orbital

1

l value for the d-orbital

2

l value for the f-orbital

3

The n value for an atomic orbital is at least one ___ than its l value.

greater

A substance is ___ if it has one or more unpaired electrons.

paramagnetic

A substance is ___ if it has no unpaired electrons.

diamagnetic

Groups are classified as the ___ of the periodic table.

columns

Periods are classified as the ___ of the periodic table.

rows

Order in which atomic orbitals fill…

1s, 2s, 2p, 3s, 3p, 4s, 3d, et cetera

Maximum amount of electrons that can fit in an orbital

2

Total electrons possible in s-orbitals

2

Total electrons possible in p-orbitals

6

Total electrons possible in d-orbitals

10

Total electrons possible in f-orbitals

14

Down a group, Z* ___

remains constant

Across a period, Z* ___

increases