Memorizing

Ammonium ion

Formula: $NH_4^+$, Charge: $+1$

Hydroxide ion

Formula: $OH^-$, Charge: $-1$

Nitrate ion

Formula: $NO_3^-$, Charge: $-1$

Nitrite ion

Formula: $NO_2^-$, Charge: $-1$

Acetate ion

Formula: $C_2H_3O_2^-$, Charge: $-1$

Cyanide ion

Formula: $CN^-$, Charge: $-1$

Hydrogen carbonate (bicarbonate) ion

Formula: $HCO_3^-$, Charge: $-1$

Hydrogen sulfate ion

Formula: $HSO_4^-$, Charge: $-1$

Permanganate ion

Formula: $MnO_4^-$, Charge: $-1$

Hypochlorite ion

Formula: $ClO^-$, Charge: $-1$

Chlorite ion

Formula: $ClO_2^-$, Charge: $-1$

Chlorate ion

Formula: $ClO_3^-$, Charge: $-1$

Perchlorate ion

Formula: $ClO_4^-$, Charge: $-1$

Sulfate ion

Formula: $SO_4^{2-}$, Charge: $-2$

Sulfite ion

Formula: $SO_3^{2-}$, Charge: $-2$

Carbonate ion

Formula: $CO_3^{2-}$, Charge: $-2$

Chromate ion

Formula: $CrO_4^{2-}$, Charge: $-2$

Dichromate ion

Formula: $Cr_2O_7^{2-}$, Charge: $-2$

Peroxide ion

Formula: $O_2^{2-}$, Charge: $-2$

Phosphate ion

Formula: $PO_4^{3-}$, Charge: $-3$

Phosphite ion

Formula: $PO_3^{3-}$, Charge: $-3$

-ate vs. -ite oxyanion suffix rule

The ion ending in -ate has more oxygen atoms than the related ion ending in -ite (for example, $NO_3^-$ vs. $NO_2^-$ and $SO_4^{2-}$ vs. $SO_3^{2-}$).

Oxyanion prefix and suffix hierarchy (oxygen count)

Hypo- + -ite = Least oxygen (1); -ite = Less oxygen (2); -ate = More oxygen (3); Per- + -ate = Most oxygen (4).

Hypo- + -ite oxyanion rule

Indicates the ion with the least oxygen in a related series, typically having 1 oxygen atom (e.g., hypochlorite, $ClO^-$).

-ite oxyanion rule

Indicates the ion with fewer oxygen atoms in a related series, typically having 2 oxygen atoms (e.g., chlorite, $ClO_2^-$).

-ate oxyanion rule

Indicates the ion with more oxygen atoms in a related series, typically having 3 oxygen atoms (e.g., chlorate, $ClO_3^-$).

Per- + -ate oxyanion rule

Indicates the ion with the most oxygen in a related series, typically having 4 oxygen atoms (e.g., perchlorate, $ClO_4^-$).

Acid naming rule: -ide anion ending

The acid is named with the prefix hydro- and the suffix -ic acid (e.g., chloride becomes hydrochloric acid, $HCl$).

Acid naming rule: -ate anion ending

The acid is named by changing the anion suffix -ate to -ic acid (e.g., nitrate becomes nitric acid, $HNO_3$).

Acid naming rule: -ite anion ending

The acid is named by changing the anion suffix -ite to -ous acid (e.g., nitrite becomes nitrous acid, $HNO_2$).

Relationship between acid naming and acid strength

An acid's systematic name indicates its anion composition, not whether the acid is chemically strong or weak.

Typical charge of Group 1 metal cations

$$+1$$

Typical charge of Group 2 metal cations

$$+2$$

Typical charge of aluminum in ionic compounds

$$+3$$

Typical charge of halogens in binary ionic compounds

$$-1$$

Typical charge of oxygen in ordinary binary ionic compounds

$$-2$$

Rule for parentheses in ionic chemical formulas

Parentheses enclose a polyatomic ion whenever a subscript greater than 1 is needed to balance overall charge (e.g., $Ca(NO_3)_2$).

Meaning of Roman numerals in transition metal names

Indicates the specific positive charge or oxidation state of the metal cation (e.g., iron(III) represents $Fe^{3+}$ in $FeCl_3$).

Hydrochloric acid

Strong acid with the formula $HCl$

Hydrobromic acid

Strong acid with the formula $HBr$

Hydroiodic acid

Strong acid with the formula $HI$

Nitric acid

Strong acid with the formula $HNO_3$

Sulfuric acid

Strong acid with the formula $H_2SO_4$

Perchloric acid

Strong acid with the formula $HClO_4$

Hydrofluoric acid

Weak acid with the formula $HF$

Acetic acid

Weak acid with the formula $HC_2H_3O_2$

Phosphoric acid

Weak acid with the formula $H_3PO_4$

Lithium hydroxide

Strong base with the formula $LiOH$

Sodium hydroxide

Strong base with the formula $NaOH$

Potassium hydroxide

Strong base with the formula $KOH$

Calcium hydroxide

Strong base with the formula $Ca(OH)_2$

Strontium hydroxide

Strong base with the formula $Sr(OH)_2$

Barium hydroxide

Strong base with the formula $Ba(OH)_2$

Ammonia

Common weak base with the formula $NH_3$

General solubility: Group 1 and ammonium salts

Soluble in water.

General solubility: Nitrate salts

Soluble in water.

General solubility: Acetate salts

Generally soluble in water.

General solubility: Halide salts (chlorides, bromides, iodides)

Usually soluble, with key exceptions such as $Ag^+$ and $Pb^{2+}$.

General solubility: Sulfate salts

Usually soluble, with key exceptions such as $Ba^{2+}$ and $Pb^{2+}$.

General solubility: Carbonate and phosphate salts

Usually insoluble, except when paired with Group 1 metal cations or ammonium ($NH_4^+$).

General solubility: Hydroxide salts

Usually insoluble, except when paired with Group 1 metal cations or heavier Group 2 cations ($Ca^{2+}$, $Sr^{2+}$, $Ba^{2+}$).

Seven diatomic elements

$H_2$, $N_2$, $O_2$, $F_2$, $Cl_2$, $Br_2$, and $I_2$

BrINClHOF mnemonic

A memory aid for the seven diatomic elements: bromine ($Br_2$), iodine ($I_2$), nitrogen ($N_2$), chlorine ($Cl_2$), hydrogen ($H_2$), oxygen ($O_2$), and fluorine ($F_2$).

General reaction products: $\text{Acid} + \text{carbonate} \rightarrow$

$$\text{Salt} + H_2O + CO_2$$

General reaction products: $\text{Acid} + \text{bicarbonate} \rightarrow$

$$\text{Salt} + H_2O + CO_2$$

Three products formed when an acid reacts with a metal carbonate

A salt, water ($H_2O$), and carbon dioxide ($CO_2$)

Three products formed when an acid reacts with a metal bicarbonate

A salt, water ($H_2O$), and carbon dioxide ($CO_2$)

Characteristic gas released during acid-carbonate and acid-bicarbonate reactions

Carbon dioxide ($CO_2$)