Question

consider the sulfur difluoride (sf₂) molecule. what is the central atom? enter its chemical symbol. how many lone pairs are around the central atom? what is the ideal angle between the sulfur - fluorine bonds? compared to the ideal angle, you would expect the actual angle between the sulfur - fluorine bonds to be... select: about the same, bigger, smaller

Explanation:

Step1: Identify central atom

In $SF_2$, sulfur (S) is the central atom as it is less electronegative than fluorine and can form more bonds.

Step2: Determine lone - pairs

Sulfur has 6 valence electrons. It forms 2 bonds with fluorine atoms. So the number of lone - pairs is $\frac{6 - 2}{2}=2$.

Step3: Find ideal bond - angle

The electron - pair geometry around the sulfur atom in $SF_2$ is tetrahedral (2 bonding pairs and 2 lone pairs). The ideal bond - angle in a tetrahedral geometry is 109.5°.

Step4: Compare ideal and actual bond - angle

Lone - pair - lone - pair repulsion is greater than lone - pair - bonding - pair repulsion which is greater than bonding - pair - bonding - pair repulsion. The presence of 2 lone pairs on sulfur in $SF_2$ compresses the S - F bonds, making the actual bond - angle smaller than the ideal bond - angle.

Answer:

1. S
2. 2
3. 109.5
4. smaller