Naming and Writing Formulas for Acids and Bases

1. Binary Acids vs. Oxyacids

• Definition of Binary Acids: Compounds of hydrogen and one other element (usually a halogen) that dissolve in water to form acidic solutions. Ex: Hydrochloric acid (HCl).

• Definition of Oxyacids: Compounds containing hydrogen, oxygen, and at least one other element that dissolve in water to form acidic solutions. Ex: Sulfuric acid ($H<em>2SO</em>4$).

• Differences: Binary acids contain only hydrogen and one other element; oxyacids contain hydrogen, oxygen, and another element.
  Question (MCQ): Which of the following is a binary acid?
  
  a) $H<em>2SO</em>4$ b) HCl c) $HNO<em>3$ d) $CH</em>3COOH$
  Answer: b) HCl

2. Naming and Writing Formulas for Binary Acids

• Rules for Naming Binary Acids:

1. Start with 'hydro-'.

2. Add the name of the non-hydrogen element, modified to end with '-ic'.

3. Add 'acid'.

• Examples of Naming Binary Acids:

1. HCl: Hydrochloric acid

2. HBr: Hydrobromic acid

• Rules for Writing Formulas for Binary Acids:

1. Identify the elements (hydrogen and one other).

2. Write hydrogen first (H).

3. Write the symbol for the other element.

4. Balance the charges.

• Examples of Writing Formulas for Binary Acids:

1. Hydroiodic acid: HI

2. Hydrosulfuric acid: $H_2S$
   Question (Free Response): Explain the steps to write the formula for hydrofluoric acid.
   Answer: 1. Identify the elements: hydrogen (H) and fluorine (F). 2. Write hydrogen first: H. 3. Write the symbol for fluorine: F. 4. Since both hydrogen and fluorine have a charge of +1 and -1 respectively, the charges are balanced, so the formula is HF.

3. Naming and Writing Formulas for Oxyacids

• Rules for Naming Oxyacids:

1. Identify the polyatomic ion.

2. If the ion ends in '-ate', change to '-ic' and add 'acid'.

3. If the ion ends in '-ite', change to '-ous' and add 'acid'.

• Examples of Naming Oxyacids:

1. $H<em>2SO</em>4$: Sulfuric acid (sulfate -> sulfuric)

2. $HNO_2$: Nitrous acid (nitrite -> nitrous)

• Rules for Writing Formulas for Oxyacids:

1. Identify the polyatomic ion and its charge.

2. Determine how many $H^+$ ions are needed to neutralize the charge.

3. Write the formula with hydrogen ions first, followed by the polyatomic ion.

• Examples of Writing Formulas for Oxyacids:

1. Phosphoric acid: $H<em>3PO</em>4$

2. Carbonic acid: $H<em>2CO</em>3$
   Question (MCQ): What is the correct name for $H<em>2CO</em>3$?
   
   a) Carbonate acid b) Carbonic acid c) Carbonous acid d) Hydrocarbonic acid
   Answer: b) Carbonic acid

4. Naming and Writing Formulas for Bases

• Rules for Naming Bases:

1. Most bases are named as hydroxides of metals.

2. Name the metal first.

3. Follow with 'hydroxide'.

• Examples of Naming Bases:

1. NaOH: Sodium hydroxide

2. $Ca(OH)_2$: Calcium hydroxide

• Rules for Writing Formulas for Bases:

1. Identify the metal and its charge.

2. Write the symbol for the metal.

3. Write the hydroxide ion ($OH^-$).

4. Balance the charges to ensure the formula is neutral using subscripts.
   Question (Free Response): Describe the general formula for naming bases and provide an example.
   Answer: The general formula for naming bases involves naming the metal cation first, followed by 'hydroxide'. For example, KOH is named potassium hydroxide.

5. Additional Questions

Question (MCQ): Which of the following acids is named incorrectly?

a) HBr: Hydrobromic acid b) $H<em>2SO</em>3$: Sulfurous acid c) HClO: Hypochlorous acid d) $HNO<em>3$: Nitrous acid Answer: d) $HNO</em>3$: Nitrous acid (should be nitric acid)

Question (MCQ): Which of the following is NOT a base?

a) KOH b) $Mg(OH)<em>2$ c) $CH</em>3OH$ d) NaOH
Answer: c) $CH_3OH$

Question (MCQ): What is the chemical formula for perchloric acid?

a) HClO b) $HClO<em>2$ c) $HClO</em>3$ d) $HClO<em>4$ Answer: d) $HClO</em>4$

Question (MCQ): What is the name of the acid with the formula HF?

a) Fluoric acid b) Hydrofluoric acid c) Fluorous acid d) Perfluoric acid
Answer: b) Hydrofluoric acid

Question (Free Response): Explain how to determine the formula of an acid formed from the polyatomic ion phosphate ($PO<em>4^{-3}$). Answer: To determine the formula of an acid formed from the phosphate ion ($PO</em>4^{-3}$), you need to add enough hydrogen ions ($H^+$) to neutralize the -3 charge of the phosphate ion. Since each hydrogen ion has a +1 charge, you need three hydrogen ions to neutralize the phosphate ion. Therefore, the formula for phosphoric acid is $H<em>3PO</em>4$.

Question (Free Response): Describe the steps to write the formula