Free Printable Naming Ionic and Covalent Compounds Worksheets - Free Printable

Here is the completed worksheet with formulas and classifications for each compound, followed by a detailed explanation of the reasoning.

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Completed Worksheet:

| Name of the Compound | Formulas | Ionic or Covalent? |
|-----------------------------|--------------------|--------------------|
| Lithium Chloride | LiCl | I |
| Ammonium Permanganate | NH₄MnO₄ | I |
| Carbon Disulfide | CS₂ | C |
| Silver Nitrate | AgNO₃ | I |
| Tin(IV) Fluoride | SnF₄ | I |
| Iron(III) Phosphate | FePO₄ | I |
| Beryllium Nitrite | Be(NO₂)₂ | I |
| Sulfur Trioxide | SO₃ | C |
| Carbon Tetrafluoride | CF₄ | C |
| Barium Dichromate | BaCr₂O₇ | I |
| Aluminum Acetate | Al(C₂H₃O₂)₃ | I |
| Silicon Dioxide | SiO₂ | C |
| Ammonia | NH₃ | C |
| Magnesium Phosphide | Mg₃P₂ | I |
| Copper(I) Iodide | CuI | I |

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Explanation & Reasoning:

#### 🔹 Ionic Compounds (I):
Formed between metals and nonmetals (or polyatomic ions). They involve electron transfer, resulting in cations (+) and anions (-) held together by electrostatic forces.

1. Lithium Chloride (LiCl)
- Li⁺ (metal) + Cl⁻ (nonmetal) → ionic.
2. Ammonium Permanganate (NH₄MnO₄)
- NH₄⁺ (polyatomic cation) + MnO₄⁻ (polyatomic anion) → ionic.
3. Silver Nitrate (AgNO₃)
- Ag⁺ (metal) + NO₃⁻ (polyatomic ion) → ionic.
4. Tin(IV) Fluoride (SnF₄)
- Sn⁴⁺ (metal) + F⁻ (nonmetal) → ionic.
5. Iron(III) Phosphate (FePO₄)
- Fe³⁺ (metal) + PO₄³⁻ (polyatomic ion) → ionic.
6. Beryllium Nitrite (Be(NO₂)₂)
- Be²⁺ (metal) + NO₂⁻ (polyatomic ion) → ionic. *Note: parentheses needed because two nitrite ions are required.*
7. Barium Dichromate (BaCr₂O₇)
- Ba²⁺ (metal) + Cr₂O₇²⁻ (polyatomic ion) → ionic.
8. Aluminum Acetate (Al(C₂H₃O₂)₃)
- Al³⁺ (metal) + C₂H₃O₂⁻ (acetate ion) → ionic. *Parentheses needed for three acetate groups.*
9. Magnesium Phosphide (Mg₃P₂)
- Mg²⁺ (metal) + P³⁻ (nonmetal) → ionic. *Criss-cross charges: Mg₃P₂.*
10. Copper(I) Iodide (CuI)
- Cu⁺ (metal) + I⁻ (nonmetal) → ionic.

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#### 🔹 Covalent Compounds (C):
Formed between two nonmetals. Atoms share electrons to form molecules.

1. Carbon Disulfide (CS₂)
- C (nonmetal) + S (nonmetal) → covalent. Prefix “di-” indicates 2 sulfur atoms.
2. Sulfur Trioxide (SO₃)
- S (nonmetal) + O (nonmetal) → covalent. Prefix “tri-” = 3 oxygen atoms.
3. Carbon Tetrafluoride (CF₄)
- C (nonmetal) + F (nonmetal) → covalent. Prefix “tetra-” = 4 fluorine atoms.
4. Silicon Dioxide (SiO₂)
- Si (metalloid, but behaves as nonmetal in compounds) + O (nonmetal) → covalent. Often treated as covalent/molecular.
5. Ammonia (NH₃)
- N (nonmetal) + H (nonmetal) → covalent. Common name for nitrogen trihydride.

> 💡 Note on Silicon Dioxide: Although silicon is a metalloid, SiO₂ forms a giant covalent network (like diamond), so it’s classified as covalent in introductory chemistry.

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✔ Key Rules Used:

- Ionic: Metal + Nonmetal OR Metal + Polyatomic Ion OR Polyatomic Ion + Polyatomic Ion.
- Covalent: Nonmetal + Nonmetal (use prefixes: mono-, di-, tri-, etc.).
- Polyatomic Ions: Memorized (e.g., NO₃⁻, NH₄⁺, PO₄³⁻, Cr₂O₇²⁻, C₂H₃O₂⁻, NO₂⁻).
- Roman Numerals: Indicate variable charge metals (e.g., Fe³⁺, Sn⁴⁺, Cu⁺).
- Criss-Cross Method: For ionic compounds, swap charges to subscripts (simplify if possible).

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This worksheet reinforces naming conventions, formula writing, and the fundamental distinction between ionic and covalent bonding based on element types. Let me know if you’d like practice naming the formulas back!