chemistry worksheet on naming and writing compounds. - Free Printable

Here is the complete solution to your Chemistry Worksheet on Naming and Writing Compounds, with explanations for each part.

---

## 🔍 KEY:
- I = Ionic compound (metal + nonmetal or polyatomic ion)
- M = Molecular compound (nonmetal + nonmetal)
- Use prefixes: B = Binary, N = Nonoxy (no oxygen), O = Oxyacid (contains H, O, and another element)

> 💡 REMINDER: Use Roman numerals for transition metals that have variable charges. Use prefixes only for binary molecular compounds.

---

# ✔ PART 1: Name these compounds

We’ll identify if it’s I or M, then name it accordingly.

---

1. NaOH → I

- Sodium hydroxide
*(Ionic: Na⁺ and OH⁻ — common base)*

2. HBr (aq) → M (O)

- Hydrobromic acid
*(Aqueous HBr = oxyacid? Actually, it’s a binary acid — but since it’s aqueous and starts with H, we name as “hydro___ic acid”)*
✔ Note: Binary acids (H + nonmetal) in aqueous form are named as “hydro___ic acid”. So this is M (N) — nonoxy acid.
➡️ Correction: M (N) → Hydrobromic acid

3. H₂S (g) → M (N)

- Dihydrogen sulfide
*(Gaseous — so not acid; molecular, binary, no oxygen → use prefixes)*

4. HClO₃ → M (O)

- Chloric acid
*(Oxyacid: H + Cl + O — chlorate ion → chloric acid)*

5. Cu(ClO₄)₂ → I

- Copper(II) perchlorate
*(Ionic: Cu²⁺ and ClO₄⁻ — copper is transition metal → use Roman numeral)*

6. H₂SO₄ → M (O)

- Sulfuric acid
*(Common oxyacid — sulfate ion → sulfuric acid)*

7. NaBr → I

- Sodium bromide
*(Ionic: Na⁺ and Br⁻ — no transition metal, no prefix needed)*

8. Hg(CN)₂ → I

- Mercury(II) cyanide
*(Ionic: Hg²⁺ and CN⁻ — mercury is transition metal → Roman numeral)*

9. SrCO₃ → I

- Strontium carbonate
*(Ionic: Sr²⁺ and CO₃²⁻ — no transition metal needing Roman numeral)*

10. (NH₄)₂SO₄ → I

- Ammonium sulfate
*(Ionic: NH₄⁺ and SO₄²⁻ — polyatomic ions)*

11. FeO → I

- Iron(II) oxide
*(Ionic: Fe²⁺ and O²⁻ — iron is transition metal → Roman numeral)*

12. Se₄N₃ → M (N)

- Tetraselenium trinitride
*(Molecular, binary, no oxygen → use prefixes)*

13. CO₂ → M (B)

- Carbon dioxide
*(Molecular, binary, no transition metal → use prefixes)*

14. PCl₅ → M (B)

- Phosphorus pentachloride
*(Molecular, binary → prefixes)*

15. SF₆ → M (B)

- Sulfur hexafluoride
*(Molecular, binary → prefixes)*

16. CoCl₂ → I

- Cobalt(II) chloride
*(Ionic: Co²⁺ and Cl⁻ — cobalt is transition metal → Roman numeral)*

17. H₂CO₃ → M (O)

- Carbonic acid
*(Oxyacid: derived from carbonate ion → carbonic acid)*

18. HNO₃ → M (O)

- Nitric acid
*(Oxyacid: nitrate ion → nitric acid)*

19. Fe(MnO₄)₃ → I

- Iron(III) permanganate
*(Ionic: Fe³⁺ and MnO₄⁻ — iron is transition metal → Roman numeral)*

20. Ni(NO₃)₂ → I

- Nickel(II) nitrate
*(Ionic: Ni²⁺ and NO₃⁻ — nickel is transition metal → Roman numeral)*

---

# ✔ PART 2: Give the correct formula

We’ll write formulas based on names.

---

1. zinc phosphate → Zn₃(PO₄)₂

- Zn²⁺ and PO₄³⁻ → cross charges → Zn₃(PO₄)₂

2. tin(II)phosphate → Sn₃(PO₄)₂

- Sn²⁺ and PO₄³⁻ → cross charges → Sn₃(PO₄)₂

3. barium chromate → BaCrO₄

- Ba²⁺ and CrO₄²⁻ → 1:1 ratio → BaCrO₄

4. aluminum acetate → Al(C₂H₃O₂)₃

- Al³⁺ and C₂H₃O₂⁻ → need 3 acetates → Al(C₂H₃O₂)₃

5. iodine pentoxide → I₂O₅

- Molecular, binary → I₂O₅ (prefixes: penta = 5 O, di = 2 I)

6. ammonium acetate → NH₄C₂H₃O₂

- NH₄⁺ and C₂H₃O₂⁻ → 1:1 → NH₄C₂H₃O₂

7. mercury(II)sulfate → HgSO₄

- Hg²⁺ and SO₄²⁻ → 1:1 → HgSO₄

8. sodium dihydrogen phosphate → NaH₂PO₄

- Na⁺ and H₂PO₄⁻ → 1:1 → NaH₂PO₄

9. phosphorous acid → H₃PO₃

- Oxyacid: phosphite ion (PO₃³⁻) → H₃PO₃

10. acetic acid → HC₂H₃O₂ or CH₃COOH

- Common name → HC₂H₃O₂ (molecular formula)

11. hydrochloric acid → HCl

- Binary acid → HCl (aqueous form, but formula is HCl)

12. Chromic acid → H₂CrO₄

- From chromate ion (CrO₄²⁻) → H₂CrO₄

13. dinitrogen monoxide → N₂O

- Molecular, binary → N₂O (di=2 N, mono=1 O)

14. carbon tetrachloride → CCl₄

- Molecular, binary → CCl₄

15. iodine monobromide → IBr

- Molecular, binary → IBr

16. hydrocyanic acid → HCN

- Binary acid (H + CN) → HCN (aqueous form)

17. sulfuric acid → H₂SO₄

- Common oxyacid → H₂SO₄

18. silver chloride → AgCl

- Ionic: Ag⁺ and Cl⁻ → AgCl (silver has fixed +1 charge → no Roman numeral)

19. lead(IV)sulfide → PbS₂

- Pb⁴⁺ and S²⁻ → cross charges → PbS₂

20. dichlorine heptoxide → Cl₂O₇

- Molecular, binary → Cl₂O₇ (di=2 Cl, hepta=7 O)

---

## 📝 FINAL ANSWER SUMMARY:

---

PART 1: Names

| # | Compound | Type | Name |
|---|----------------|------|---------------------------|
| 1 | NaOH | I | Sodium hydroxide |
| 2 | HBr (aq) | M(N) | Hydrobromic acid |
| 3 | H₂S (g) | M(N) | Dihydrogen sulfide |
| 4 | HClO₃ | M(O) | Chloric acid |
| 5 | Cu(ClO₄)₂ | I | Copper(II) perchlorate |
| 6 | H₂SO₄ | M(O) | Sulfuric acid |
| 7 | NaBr | I | Sodium bromide |
| 8 | Hg(CN)₂ | I | Mercury(II) cyanide |
| 9 | SrCO₃ | I | Strontium carbonate |
|10 | (NH₄)₂SO₄ | I | Ammonium sulfate |
|11 | FeO | I | Iron(II) oxide |
|12 | Se₄N₃ | M(N) | Tetraselenium trinitride |
|13 | CO₂ | M(B) | Carbon dioxide |
|14 | PCl₅ | M(B) | Phosphorus pentachloride |
|15 | SF₆ | M(B) | Sulfur hexafluoride |
|16 | CoCl₂ | I | Cobalt(II) chloride |
|17 | H₂CO₃ | M(O) | Carbonic acid |
|18 | HNO₃ | M(O) | Nitric acid |
|19 | Fe(MnO₄)₃ | I | Iron(III) permanganate |
|20 | Ni(NO₃)₂ | I | Nickel(II) nitrate |

---

PART 2: Formulas

| # | Name | Formula |
|---|--------------------------|-----------------|
| 1 | zinc phosphate | Zn₃(PO₄)₂ |
| 2 | tin(II)phosphate | Sn₃(PO₄)₂ |
| 3 | barium chromate | BaCrO₄ |
| 4 | aluminum acetate | Al(C₂H₃O₂)₃ |
| 5 | iodine pentoxide | I₂O₅ |
| 6 | ammonium acetate | NH₄C₂H₃O₂ |
| 7 | mercury(II)sulfate | HgSO₄ |
| 8 | sodium dihydrogen phosphate | NaH₂PO₄ |
| 9 | phosphorous acid | H₃PO₃ |
|10 | acetic acid | HC₂H₃O₂ |
|11 | hydrochloric acid | HCl |
|12 | Chromic acid | H₂CrO₄ |
|13 | dinitrogen monoxide | N₂O |
|14 | carbon tetrachloride | CCl₄ |
|15 | iodine monobromide | IBr |
|16 | hydrocyanic acid | HCN |
|17 | sulfuric acid | H₂SO₄ |
|18 | silver chloride | AgCl |
|19 | lead(IV)sulfide | PbS₂ |
|20 | dichlorine heptoxide | Cl₂O₇ |

---

✔ You’re all set! This worksheet covers naming rules for ionic and molecular compounds, including acids and transition metals. Keep practicing — you’ve got this!

Let me know if you’d like flashcards or a printable version!