Understand the two primary systems for naming acids: one for binary acids (starting with 'hydro-') and one for oxyacids (based on the name of the polyatomic anion).
How can you generally identify a compound as an acid from its chemical formula?
Acids are typically compounds that produce hydrogen ions (\(H^{+}\)) when dissolved in water. Their formulas usually start with hydrogen (e.g., \(HCl\), \(H_2SO_4\)). The state symbol (aq) for aqueous is often used.
What are the two main categories of acids for naming purposes?
1. Binary acids: Contain hydrogen and one other nonmetal element.
2. Oxyacids: Contain hydrogen, oxygen, and one other nonmetal element.
What is the rule for naming a binary acid?
Use the prefix 'hydro-', followed by the root of the nonmetal's name with an '-ic' suffix, and end with the word 'acid'. Formula: hydro + (nonmetal root) + ic + acid.
Name the acid \(HCl(aq)\).
Hydrochloric acid
Name the acid \(HBr(aq)\).
Hydrobromic acid
Name the acid \(H_2S(aq)\).
Hydrosulfuric acid
What is the chemical formula for hydrofluoric acid?
$$ HF(aq) $$
How is the name of an oxyacid determined?
The name is based on the name of the polyatomic oxyanion it contains. The 'hydro-' prefix is NOT used.
What is the naming rule for an oxyacid formed from an anion ending in '-ate'?
If the anion name ends in '-ate', the acid name ends in '-ic acid'. Mnemonic: 'I ate something icky.'
What is the naming rule for an oxyacid formed from an anion ending in '-ite'?
If the anion name ends in '-ite', the acid name ends in '-ous acid'. Mnemonic: 'A snake bite is venomous.'
The anion nitrate is \(NO_3^{-}\). What is the name of the acid \(HNO_3\)?
Nitric acid. (Nitrate becomes Nitric).
The anion nitrite is \(NO_2^{-}\). What is the name of the acid \(HNO_2\)?
Nitrous acid. (Nitrite becomes Nitrous).
Name the acid \(H_2SO_4\), which contains the sulfate ion (\(SO_4^{2-}\)).
Sulfuric acid. (Sulfate becomes Sulfuric).
Name the acid \(H_2SO_3\), which contains the sulfite ion (\(SO_3^{2-}\)).
Sulfurous acid. (Sulfite becomes Sulfurous).
Name the acid \(HClO_4\), which contains the perchlorate ion (\(ClO_4^{-}\)).
Perchloric acid. The prefix 'per-' from the anion is retained in the acid name.
Name the acid \(HClO\), which contains the hypochlorite ion (\(ClO^{-}\)).
Hypochlorous acid. The prefix 'hypo-' from the anion is retained in the acid name.
What is the chemical formula for phosphoric acid?
$$ H_3PO_4 $$ (Derived from the phosphate ion, \(PO_4^{3-}\), which requires three \(H^{+}\) ions to balance the charge.)
What is the chemical formula for acetic acid?
$$ HC_2H_3O_2 $$ (Derived from the acetate ion, \(C_2H_3O_2^{-}\). The first H is the acidic proton.)
What is the name of the compound \(HCl(g)\) (hydrogen chloride gas) vs \(HCl(aq)\)?
As a gas, \(HCl(g)\) is named as a molecular compound: hydrogen chloride. When dissolved in water, \(HCl(aq)\) is named as an acid: hydrochloric acid.
