Question

practice problems - type ii chemical formulas
directions: write the correct formula for the compounds below.

1. iron (ii) chloride
2. copper (i) sulfide
3. lead (iv) iodide
4. tin (ii) fluoride
5. zinc bromide
6. tin (ii) oxide
7. chromium (iii) oxide
8. gold (i) iodide
9. manganese (ii) nitride
10. cobalt (iii) phosphide
11. iron (iii) chloride
12. copper (ii) sulfide
13. lead (ii) bromide
14. tin (iv) iodide
15. silver sulfide
16. tin (iv) oxide
17. manganese (iii) chloride
18. chromium (ii) nitride
19. gold (iii) oxide
20. cobalt (ii) phosphide
21. tin (ii) sulfide
22. silver bromide
23. gold (iii) bromide
24. manganese (ii) oxide
25. chromium (ii) chloride
26. lead (iv) nitride
27. cobalt (iii) oxide
28. copper (ii) iodide
29. tin (iv) fluoride
30. iron (ii) phosphide

Explanation:

Step1: Determine the ions

For each compound, identify the cation and anion. For example, for Iron (II) chloride:

• Cation: \(Fe^{2+}\) (Iron (II) ion)
• Anion: \(Cl^{-}\) (Chloride ion)

Step2: Balance the charges

The overall charge of the compound must be zero. Using the criss - cross method:
For \(Fe^{2+}\) and \(Cl^{-}\), we need 2 \(Cl^{-}\) ions to balance the \(+ 2\) charge of \(Fe^{2+}\). So the formula is \(FeCl_{2}\)

Repeating this process for all compounds:

1. Iron (II) chloride: \(FeCl_{2}\)
2. Copper (I) sulfide: \(Cu_{2}S\) (since \(Cu^{+}\) and \(S^{2 -}\), need 2 \(Cu^{+}\))
3. Lead (IV) iodide: \(PbI_{4}\) (\(Pb^{4+}\) and \(I^{-}\), need 4 \(I^{-}\))
4. Tin (II) fluoride: \(SnF_{2}\) (\(Sn^{2+}\) and \(F^{-}\))
5. Zinc bromide: \(ZnBr_{2}\) (\(Zn^{2+}\) and \(Br^{-}\))
6. Tin (II) oxide: \(SnO\) (\(Sn^{2+}\) and \(O^{2 -}\))
7. Chromium (III) oxide: \(Cr_{2}O_{3}\) (\(Cr^{3+}\) and \(O^{2 -}\), cross - multiply 3 and 2)
8. Gold (I) iodide: \(AuI\) (\(Au^{+}\) and \(I^{-}\))
9. Manganese (II) nitride: \(Mn_{3}N_{2}\) (\(Mn^{2+}\) and \(N^{3 -}\), cross - multiply 3 and 2)
10. Cobalt (III) phosphide: \(CoP\) (\(Co^{3+}\) and \(P^{3 -}\))
11. Iron (III) chloride: \(FeCl_{3}\) (\(Fe^{3+}\) and \(Cl^{-}\))
12. Copper (II) sulfide: \(CuS\) (\(Cu^{2+}\) and \(S^{2 -}\))
13. Lead (II) bromide: \(PbBr_{2}\) (\(Pb^{2+}\) and \(Br^{-}\))
14. Tin (IV) iodide: \(SnI_{4}\) (\(Sn^{4+}\) and \(I^{-}\))
15. Silver sulfide: \(Ag_{2}S\) (\(Ag^{+}\) and \(S^{2 -}\))
16. Tin (IV) oxide: \(SnO_{2}\) (\(Sn^{4+}\) and \(O^{2 -}\))
17. Manganese (III) chloride: \(MnCl_{3}\) (\(Mn^{3+}\) and \(Cl^{-}\))
18. Chromium (II) nitride: \(Cr_{3}N_{2}\) (\(Cr^{2+}\) and \(N^{3 -}\))
19. Gold (III) oxide: \(Au_{2}O_{3}\) (\(Au^{3+}\) and \(O^{2 -}\))
20. Cobalt (II) phosphide: \(Co_{3}P_{2}\) (\(Co^{2+}\) and \(P^{3 -}\))
21. Tin (II) sulfide: \(SnS\) (\(Sn^{2+}\) and \(S^{2 -}\))
22. Silver bromide: \(AgBr\) (\(Ag^{+}\) and \(Br^{-}\))
23. Gold (III) bromide: \(AuBr_{3}\) (\(Au^{3+}\) and \(Br^{-}\))
24. Manganese (II) oxide: \(MnO\) (\(Mn^{2+}\) and \(O^{2 -}\))
25. Chromium (II) chloride: \(CrCl_{2}\) (\(Cr^{2+}\) and \(Cl^{-}\))
26. Lead (IV) nitride: \(Pb_{3}N_{4}\) (\(Pb^{4+}\) and \(N^{3 -}\))
27. Cobalt (III) oxide: \(Co_{2}O_{3}\) (\(Co^{3+}\) and \(O^{2 -}\))
28. Copper (II) iodide: \(CuI_{2}\) (\(Cu^{2+}\) and \(I^{-}\))
29. Tin (IV) fluoride: \(SnF_{4}\) (\(Sn^{4+}\) and \(F^{-}\))
30. Iron (II) phosphide: \(Fe_{3}P_{2}\) (\(Fe^{2+}\) and \(P^{3 -}\))

Answer:

1. \(FeCl_{2}\)
2. \(Cu_{2}S\)
3. \(PbI_{4}\)
4. \(SnF_{2}\)
5. \(ZnBr_{2}\)
6. \(SnO\)
7. \(Cr_{2}O_{3}\)
8. \(AuI\)
9. \(Mn_{3}N_{2}\)
10. \(CoP\)
11. \(FeCl_{3}\)
12. \(CuS\)
13. \(PbBr_{2}\)
14. \(SnI_{4}\)
15. \(Ag_{2}S\)
16. \(SnO_{2}\)
17. \(MnCl_{3}\)
18. \(Cr_{3}N_{2}\)
19. \(Au_{2}O_{3}\)
20. \(Co_{3}P_{2}\)
21. \(SnS\)
22. \(AgBr\)
23. \(AuBr_{3}\)
24. \(MnO\)
25. \(CrCl_{2}\)
26. \(Pb_{3}N_{4}\)
27. \(Co_{2}O_{3}\)
28. \(CuI_{2}\)
29. \(SnF_{4}\)
30. \(Fe_{3}P_{2}\)