Question

Which statement best describes the properties of covalent compounds?

Answer 1

B. They may be gases, liquids, or solids at room temp.

Answer 2

Answer

Option B= They may be gases, liquids, or solids at room temperature, and have a low melting and boiling point.  

Explanation

A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding. Hence the bonding is relatively weak thus have low melting and boiling point. On the other hand, ionic compounds are formed by the transferring of electrons thus strong electrostatic forces are present and require a large amount of energy to break it apart hence boiling and melting points are high.

For example

The molecule carbon tetrachloride is a non-polar covalent molecule, CCl4. Its melting point is -23°C. By contrast, the ionic solid NaCl has a melting point of 800°C.

Properties  of Covalent Compounds

1. Gases, liquids, or solids (made of molecules)  

2. Low melting and boiling points  

3. Poor electrical conductors in all phases  

4. Many soluble in nonpolar liquids but not in water