Naming and writing formulas for ionic compounds worksheet | Live ... - Free Printable

Let's solve this step-by-step. The task is to name the ionic compounds given their formulas (on the left) and write the correct chemical formula for the named compounds (on the right).

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🔬 Rules for Naming Ionic Compounds:

1. Cations (positive ions):
- Metals with fixed charges (like Na⁺, Mg²⁺, Al³⁺) → use element name.
- Transition metals with variable charges (like Fe²⁺/Fe³⁺) → use Roman numerals in parentheses to indicate charge.
2. Anions (negative ions):
- Monatomic anions: change ending to -ide (e.g., Cl⁻ → chloride).
- Polyatomic ions: use standard names (e.g., SO₄²⁻ → sulfate).
3. Polyatomic ions: Memorize common ones like NO₃⁻ (nitrate), CO₃²⁻ (carbonate), OH⁻ (hydroxide), etc.

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## ✔ SOLUTIONS

Part A: Name the Formula

| # | Formula | Name |
|---|---------------------|--------------------------------------|
| 1 | Na₂CO₃ | Sodium carbonate |
| 2 | NaOH | Sodium hydroxide |
| 3 | MgBr₂ | Magnesium bromide |
| 4 | KCl | Potassium chloride |
| 5 | FeCl₂ | Iron(II) chloride |
| 6 | FeCl₃ | Iron(III) chloride |
| 7 | Zn(OH)₂ | Zinc hydroxide |
| 8 | Be₂SO₄ | Beryllium sulfate |
| 9 | CrF₂ | Chromium(II) fluoride |
|10 | Al₂S₃ | Aluminum sulfide |
|11 | PbO | Lead(II) oxide |
|12 | Li₃PO₄ | Lithium phosphate |
|13 | TiI₄ | Titanium(IV) iodide |
|14 | Co₃N₂ | Cobalt(II) nitride |
|15 | Mg₃P₂ | Magnesium phosphide |
|16 | Ga(NO₂)₃ | Gallium nitrite |
|17 | Ag₂SO₃ | Silver sulfite |
|18 | NH₄OH | Ammonium hydroxide |
|19 | Al(CN)₃ | Aluminum cyanide |
|20 | Be(CH₃COO)₂ | Beryllium acetate |

> 💡 Note: CH₃COO⁻ is the acetate ion, so Be(CH₃COO)₂ = beryllium acetate.

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Part B: Write the Formula from the Name

| # | Name | Formula |
|---|-----------------------------|------------------------------------|
|21 | sodium phosphide | Na₃P |
|22 | magnesium nitrate | Mg(NO₃)₂ |
|23 | lead (II) sulfite | PbSO₃ |
|24 | calcium phosphate | Ca₃(PO₄)₂ |
|25 | ammonium sulfate | (NH₄)₂SO₄ |
|26 | silver cyanide | AgCN |
|27 | aluminum sulfide | Al₂S₃ |
|28 | beryllium chloride | BeCl₂ |
|29 | copper (I) arsenide | Cu₃As |
|30 | iron (III) oxide | Fe₂O₃ |
|31 | gallium nitride | GaN |
|32 | iron (II) bromide | FeBr₂ |
|33 | vanadium (V) phosphate | V₃(PO₄)₅ |
|34 | calcium oxide | CaO |
|35 | magnesium acetate | Mg(CH₃COO)₂ or Mg(C₂H₃O₂)₂ |
|36 | aluminum sulfate | Al₂(SO₄)₃ |
|37 | copper (I) carbonate | Cu₂CO₃ |
|38 | barium oxide | BaO |
|39 | ammonium sulfite | (NH₄)₂SO₃ |
|40 | silver bromide | AgBr |

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🔍 Explanation of Key Steps

#### For Naming (Left Side):
- Na₂CO₃: Na⁺ + CO₃²⁻ → sodium carbonate
- FeCl₂ vs FeCl₃: Iron has variable charge → Fe²⁺ = iron(II), Fe³⁺ = iron(III)
- Zn(OH)₂: Zinc is usually Zn²⁺, OH⁻ is hydroxide → zinc hydroxide
- Be₂SO₄: Be²⁺ and SO₄²⁻ → balance charges: Be₂SO₄
- Al(CN)₃: Al³⁺ and CN⁻ → aluminum cyanide
- Be(CH₃COO)₂: Acetate is C₂H₃O₂⁻ or CH₃COO⁻ → beryllium acetate

#### For Formulas (Right Side):
- Sodium phosphide: Na⁺ and P³⁻ → Na₃P
- Lead(II) sulfite: Pb²⁺ and SO₃²⁻ → PbSO₃
- Calcium phosphate: Ca²⁺ and PO₄³⁻ → Ca₃(PO₄)₂ (LCM of 2 and 3 is 6)
- Ammonium sulfate: NH₄⁺ and SO₄²⁻ → (NH₄)₂SO₄
- Vanadium(V) phosphate: V⁵⁺ and PO₄³⁻ → V₃(PO₄)₅ (balance: 3×5 = 15+, 5×3 = 15−)
- Copper(I) arsenide: Cu⁺ and As³⁻ → Cu₃As
- Iron(II) bromide: Fe²⁺ and Br⁻ → FeBr₂
- Magnesium acetate: Mg²⁺ and CH₃COO⁻ → Mg(CH₃COO)₂

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✔ Final Answer Table:

| # | Name / Formula | Answer |
|---|----------------|--------|
| 1 | Na₂CO₃ | Sodium carbonate |
| 2 | NaOH | Sodium hydroxide |
| 3 | MgBr₂ | Magnesium bromide |
| 4 | KCl | Potassium chloride |
| 5 | FeCl₂ | Iron(II) chloride |
| 6 | FeCl₃ | Iron(III) chloride |
| 7 | Zn(OH)₂ | Zinc hydroxide |
| 8 | Be₂SO₄ | Beryllium sulfate |
| 9 | CrF₂ | Chromium(II) fluoride |
|10 | Al₂S₃ | Aluminum sulfide |
|11 | PbO | Lead(II) oxide |
|12 | Li₃PO₄ | Lithium phosphate |
|13 | TiI₄ | Titanium(IV) iodide |
|14 | Co₃N₂ | Cobalt(II) nitride |
|15 | Mg₃P₂ | Magnesium phosphide |
|16 | Ga(NO₂)₃ | Gallium nitrite |
|17 | Ag₂SO₃ | Silver sulfite |
|18 | NH₄OH | Ammonium hydroxide |
|19 | Al(CN)₃ | Aluminum cyanide |
|20 | Be(CH₃COO)₂ | Beryllium acetate |
|21 | sodium phosphide | Na₃P |
|22 | magnesium nitrate | Mg(NO₃)₂ |
|23 | lead (II) sulfite | PbSO₃ |
|24 | calcium phosphate | Ca₃(PO₄)₂ |
|25 | ammonium sulfate | (NH₄)₂SO₄ |
|26 | silver cyanide | AgCN |
|27 | aluminum sulfide | Al₂S₃ |
|28 | beryllium chloride | BeCl₂ |
|29 | copper (I) arsenide | Cu₃As |
|30 | iron (III) oxide | Fe₂O₃ |
|31 | gallium nitride | GaN |
|32 | iron (II) bromide | FeBr₂ |
|33 | vanadium (V) phosphate | V₃(PO₄)₅ |
|34 | calcium oxide | CaO |
|35 | magnesium acetate | Mg(CH₃COO)₂ |
|36 | aluminum sulfate | Al₂(SO₄)₃ |
|37 | copper (I) carbonate | Cu₂CO₃ |
|38 | barium oxide | BaO |
|39 | ammonium sulfite | (NH₄)₂SO₃ |
|40 | silver bromide | AgBr |

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✔ All answers are now complete and correctly formatted. Let me know if you'd like a printable version or explanations for any specific compound!