Which two molecules are compounds? NaHCO3 O3 Cl2 C8H18
The Correct Answer and Explanation is:
The two molecules that are compounds are NaHCO₃ (sodium bicarbonate) and C₈H₁₈ (octane).
Explanation:
To determine which of these molecules are compounds, we need to understand the difference between elements and compounds:
- Element: A substance made of only one type of atom. It cannot be broken down into simpler substances by chemical means. Examples: O₃ (ozone) and Cl₂ (chlorine gas), both made of only oxygen and chlorine atoms respectively.
- Compound: A substance formed when two or more different elements are chemically bonded together in fixed proportions. Examples: NaHCO₃ and C₈H₁₈.
Analysis of Each Substance:
- NaHCO₃ (Sodium bicarbonate):
- Composed of four different elements: sodium (Na), hydrogen (H), carbon (C), and oxygen (O).
- These atoms are chemically combined in a fixed ratio.
- Therefore, NaHCO₃ is a compound.
- O₃ (Ozone):
- Made entirely of oxygen atoms.
- Though it has three atoms, all are the same element, so it is not a compound; it’s an elemental molecule.
- Cl₂ (Chlorine gas):
- Composed of two chlorine atoms.
- Since both atoms are the same element, Cl₂ is not a compound, but a diatomic element.
- C₈H₁₈ (Octane):
- Made up of two different elements: carbon (C) and hydrogen (H).
- Chemically bonded in a fixed ratio (8 carbon atoms to 18 hydrogen atoms).
- Therefore, C₈H₁₈ is a compound.
Conclusion:
The two compounds are:
✅ NaHCO₃ (sodium bicarbonate)
✅ C₈H₁₈ (octane)
O₃ and Cl₂ are not compounds; they are elemental molecules.
