1. Analyzing the Options:
• (A) Solubility: Covalent compounds are generally non-polar and thus insoluble in polar solvents like water, but soluble in organic solvents. (True property)
• (B) Constitution: They consist of discrete molecules held together by intermolecular forces, rather than a lattice of ions. (True property)
• (C) Physical State: Due to varied intermolecular strengths, they can be gases ($CH_4$), liquids ($H_2O$), or soft solids ($I_2$). (True property)
2. Why (D) is Incorrect: Chemical reactions between covalent compounds involve the
breaking of existing covalent bonds and the formation of new ones. This process requires significant activation energy and time. In contrast, ionic reactions involve simple collisions between ions in solution and are nearly instantaneous.
Therefore, covalent reactions are typically
slow, making statement (D) the false property.