Chapter 2.7: Compounds: Formulates, Names, and Masses

Flashcards from Chapter 2.7 of Chemistry: The Molecular Nature of Matter and Change.

Chemical formula

Formula where element symbols and numerical subscripts show the type and number of each atom in the smallest unit of the substance

-ide

Suffix used for binary ionic compound nonmetal anions

-ic

Suffix used for transition metal with higher charge

-ous

Suffix used for transition metal with lower charge

Polyatomic ion

An ion that stays together as a charged unit in an ionic compound; written with parentheses if appearing more than once but no prefixes needed

NH⁺₄

Ammonium

OH^-

Hydroxide

ClO^-₃

Chlorate

ClO^-₄

Perchlorate

NO^-₃

Nitrate

MnO^-₄

Permanganate

CO^2-₃

Carbonate

HCO^-₃

Hydrogen carbonate (bicarbonate)

Cr₂O^2-₇

Dichromate

PO^3-₄

Phosphate

SO^2-₄

Sulfate

Oxoanion

An anion in which an element, usually a nonmetal, is bonded to one or more oxygen atoms

Naming for two oxoanions

• More: use root + “ate”

• Less: use root + “ite”

Naming for four oxoanions

• Most: use “per” + root + “ate”

• Next: use root + “ate”

• Next: use root + “ite”

• Least: use “hypo” + root + “ite”

Hydrates

Compounds with specific amounts of water in each formula unit, shown with a centered dot and said with a Greek prefix

Waters of hydration

Water molecules in a hydrate that can be removed when heating

Acid

Hydrogen-containing compounds that donate hydrogen ions to give a neutral compounds; broken up into:

• Binary acids (hydrogen and nonmetal anions)

• Oxoacids (hydrogen and an oxoanion)

Binary acid

An acid composed of hydrogen and nonmetal anion, turning nonmetals with -ide prefixes into “hydro” + root + “ic”

Oxoanion

An acid composed of hydrogen and an oxoanion

• “ate” → “ic”

• “ite” → “ous”

• + “acid”

Binary covalent compounds

Formed by two nonmetals

• Uses Greek prefixes for each part

Hydrocarbons

The simplest organic compounds, only made of carbon and hydrogen

Alkanes

The simplest type of hydrocarbons, seen in fuels

Straight-chain alkanes

The simplest alkanes, with no branches, based on a root

• Named with different roots for the first four before switching to Greek prefixes

Methane

Straight chain alkane with one carbon atom; CH₄

Ethane

Straight chain alkane with two carbon atoms; C₂H₆

Propane

Straight chain alkane with three carbon atoms; C₃H₈

Butane

Straight chain alkane with four carbon atoms; C₄H₁₀

Formula unit

What ionic compound formulas are, in relation to proportions in the compound and array

Molecular mass (formula mass)

In ionic and covalent compounds, this is the sum of atomic masses