Paper 2 · Subatomic particles, ions and bonding
Carbon tetrachloride, CCl4, is a liquid at room temperature while calcium chloride, CaCl2, is a solid. This is because...
ACCl4 molecules are held together by strong intermolecular forces of attraction, while ions in CaCl2 are held together by weak electrostatic forces.
BCCl4 molecules are held together by weak intermolecular forces of attraction, while Ca²⁺ and Cl⁻ ions in CaCl2 are held together by strong electrostatic forces.
CCCl4 is made up of ions while CaCl2 is made up of covalent molecules.
DCCl4 has a higher boiling point than CaCl2 because its molecules are larger.
Explanation: CCl4 is a simple covalent molecule held together by weak intermolecular forces, so little energy is needed to separate its molecules. CaCl2 is ionic, with strong electrostatic forces between ions that require much more energy to overcome, so it is solid at room temperature.
Derived from ZIMSEC Chemistry 5071/2 Paper 2 Theory, November 2014, Q1
