Classify the following bonds as ionic, polar covalent, or non-polar covalent and explain: The CF bond in CF4 The CaCl bond in CaCl2 The SiSi bond in Cl3SiSiCl3
The Correct Answer and Explanation is:
Bond Classification and Explanation:
- The CF bond in CF₄ – Polar Covalent
The bond between carbon (C) and fluorine (F) in carbon tetrafluoride (CF₄) is classified as polar covalent. Fluorine is significantly more electronegative than carbon. This large difference in electronegativity causes the shared electrons in the bond to be pulled more toward the fluorine atom, creating a dipole. Although the molecule CF₄ is symmetrical and non-polar overall, each individual CF bond remains polar covalent due to the unequal sharing of electrons. - The CaCl bond in CaCl₂ – Ionic
The bond between calcium (Ca) and chlorine (Cl) in calcium chloride (CaCl₂) is ionic. Calcium is a metal that readily loses two electrons to form a Ca²⁺ ion, while chlorine is a non-metal that gains one electron to form Cl⁻ ions. The transfer of electrons from calcium to chlorine leads to the formation of oppositely charged ions, which are held together by strong electrostatic forces. The resulting compound has ionic character due to the complete electron transfer from metal to non-metal. - The Si–Si bond in Cl₃Si–SiCl₃ – Non-Polar Covalent
The bond between two silicon (Si) atoms in hexachlorodisilane (Cl₃Si–SiCl₃) is non-polar covalent. Both atoms involved in the bond are identical, meaning they have the same electronegativity. As a result, the bonding electrons are shared equally between the two silicon atoms, with no separation of charge. This equal sharing leads to a non-polar covalent bond, characterized by an even distribution of electron density along the bond.
Summary of Bond Types:
- CF in CF₄ → Polar Covalent
- CaCl in CaCl₂ → Ionic
- SiSi in Cl₃Si–SiCl₃ → Non-Polar Covalent
Each bond type reflects the nature of electron sharing or transfer determined by the electronegativity difference between bonded atoms.
