MDCAT Chemistry MCQ #5381

Carbon dioxide (CO2) is a gas at room temperature, while Silicon dioxide (SiO2) is a high-melting solid. This contrast is due to:

MDCAT Chemistry MCQ #5381

  1. Question 1

    Q1. Carbon dioxide (CO2) is a gas at room temperature, while Silicon dioxide (SiO2) is a high-melting solid. This contrast is due to:

    • A) CO2 is a solid macromolecule at room temperature
    • B) SiO2 forms a giant covalent crystal lattice
    • C) SiO2 consists of discrete linear molecules
    • D) CO2 has a higher melting point than SiO2

    Answer: SiO2 forms a giant covalent crystal lattice

    Explanation: CO2 is a discrete gas molecule with weak forces, whereas SiO2 is a giant covalent macromolecule with high melting points.