Writing Chemical Formula - Chemistry - Assignment - Teachmint - Free Printable

To solve the problem, we need to write the chemical formulas for each of the given compounds. Here is the step-by-step solution:

List of Compounds and Their Chemical Formulas:

1. Water
- Water is composed of hydrogen (H) and oxygen (O). The formula is:
\[
\boxed{H_2O}
\]

2. Marble
- Marble is primarily composed of calcium carbonate (CaCO₃). The formula is:
\[
\boxed{CaCO_3}
\]

3. Calcium carbonate
- Calcium carbonate consists of calcium (Ca), carbon (C), and oxygen (O). The formula is:
\[
\boxed{CaCO_3}
\]

4. Sodium oxide
- Sodium oxide consists of sodium (Na) and oxygen (O). The formula is:
\[
\boxed{Na_2O}
\]

5. Hydrochloric acid
- Hydrochloric acid consists of hydrogen (H) and chlorine (Cl). The formula is:
\[
\boxed{HCl}
\]

6. Carbon dioxide
- Carbon dioxide consists of carbon (C) and oxygen (O). The formula is:
\[
\boxed{CO_2}
\]

7. Ammonium hydroxide
- Ammonium hydroxide consists of ammonium (NH₄) and hydroxide (OH). The formula is:
\[
\boxed{NH_4OH}
\]

8. Sodium sulphate
- Sodium sulphate consists of sodium (Na), sulfur (S), and oxygen (O). The formula is:
\[
\boxed{Na_2SO_4}
\]

9. Sodium carbonate
- Sodium carbonate consists of sodium (Na), carbon (C), and oxygen (O). The formula is:
\[
\boxed{Na_2CO_3}
\]

10. Ammonium sulphate
- Ammonium sulphate consists of ammonium (NH₄) and sulfate (SO₄). The formula is:
\[
\boxed{(NH_4)_2SO_4}
\]

11. Potassium oxide
- Potassium oxide consists of potassium (K) and oxygen (O). The formula is:
\[
\boxed{K_2O}
\]

12. Sodium chloride
- Sodium chloride consists of sodium (Na) and chlorine (Cl). The formula is:
\[
\boxed{NaCl}
\]

13. Aluminium sulphate
- Aluminium sulphate consists of aluminium (Al), sulfur (S), and oxygen (O). The formula is:
\[
\boxed{Al_2(SO_4)_3}
\]

14. Aluminium carbonate
- Aluminium carbonate consists of aluminium (Al), carbon (C), and oxygen (O). The formula is:
\[
\boxed{Al_2(CO_3)_3}
\]

15. Sodium carbonate
- Sodium carbonate consists of sodium (Na), carbon (C), and oxygen (O). The formula is:
\[
\boxed{Na_2CO_3}
\]

16. Aluminium oxide
- Aluminium oxide consists of aluminium (Al) and oxygen (O). The formula is:
\[
\boxed{Al_2O_3}
\]

17. Potassium chloride
- Potassium chloride consists of potassium (K) and chlorine (Cl). The formula is:
\[
\boxed{KCl}
\]

18. Aluminium chloride
- Aluminium chloride consists of aluminium (Al) and chlorine (Cl). The formula is:
\[
\boxed{AlCl_3}
\]

19. Ammonium chloride
- Ammonium chloride consists of ammonium (NH₄) and chloride (Cl). The formula is:
\[
\boxed{NH_4Cl}
\]

20. Sulphuric acid
- Sulphuric acid consists of hydrogen (H), sulfur (S), and oxygen (O). The formula is:
\[
\boxed{H_2SO_4}
\]

Final Answer:

\[
\boxed{
\begin{aligned}
1. & \ H_2O \\
2. & \ CaCO_3 \\
3. & \ CaCO_3 \\
4. & \ Na_2O \\
5. & \ HCl \\
6. & \ CO_2 \\
7. & \ NH_4OH \\
8. & \ Na_2SO_4 \\
9. & \ Na_2CO_3 \\
10. & \ (NH_4)_2SO_4 \\
11. & \ K_2O \\
12. & \ NaCl \\
13. & \ Al_2(SO_4)_3 \\
14. & \ Al_2(CO_3)_3 \\
15. & \ Na_2CO_3 \\
16. & \ Al_2O_3 \\
17. & \ KCl \\
18. & \ AlCl_3 \\
19. & \ NH_4Cl \\
20. & \ H_2SO_4 \\
\end{aligned}
}
\]