Question

Arrange the following in increasing order of covalent character: (A) LiF
(B) LiBr
(C) LiCl
(D) LiI

• A. (A), (B), (C), (D)
• B. (A), (C), (B), (D)
• C. (B), (A), (D), (C)
• D. (C), (B), (A), (D)

Hint:

The covalent character of the bond increases as the size of the halide anion increases.

Answer 1

The Correct Option is A

Step 1: Defining Covalent Character.
Covalent character describes the extent to which electrons are shared between atoms in a molecule. Ionic character generally diminishes with increasing anion size, thus increasing the covalent character of the bond. Conversely, a larger electronegativity difference between atoms results in higher ionic character and lower covalent character. Consequently, smaller anions contribute to more ionic compounds, which have less covalent character.

Step 2: Evaluating Compounds.
- (A) LiF: Lithium fluoride exhibits the least covalent character due to fluorine's small size and high electronegativity, creating a highly ionic bond. - (B) LiBr: The larger bromine atom compared to fluorine results in a less ionic bond and therefore higher covalent character than LiF. - (C) LiCl: Chlorine's larger size than bromine further reduces ionic character, increasing covalent character. - (D) LiI: Iodine, being the largest halogen, leads to the highest covalent character among these compounds.

Step 3: Determination.
The compounds arranged by increasing covalent character are: \[ \text{LiF} < \text{LiBr} < \text{LiCl} < \text{LiI} \] This corresponds to option (1): (A), (B), (C), (D).