Question

The total number of sigma bonds in P$_4$O$_{10}$ is:

• A. 6
• B. 7
• C. 16
• D. 17

Answer 1

The Correct Option is C

P₄O₁₀ is a molecular compound with a specific arrangement of atoms that can be analyzed to determine the number of sigma (σ) bonds present. The structure comprises four phosphorus (P) atoms and ten oxygen (O) atoms. In the P₄O₁₀ molecule, the central P₄ forms a tetrahedral structure where each phosphorus atom is bonded to three others, creating six P-P single bonds. Each phosphorus is further bonded to four oxygen atoms, connecting through single bonds. Therefore, the bonds can be counted as follows:

1. P-P bonds: There are six P-P single bonds formed among the four phosphorus atoms.

2. P-O bonds: Each phosphorus atom forms four P-O single bonds, resulting in 4 × 4 = 16 P-O single bonds.

Adding these bonds together, the total number of σ bonds is calculated:
Total σ bonds = 6 (P-P) + 16 (P-O) = 22.

Hence, each pair of atoms forms a σ bond in covalent bondings, and the double bond between P and O has one σ bond. Therefore, the correct option counting only P-O single bonds without considering any double bonds is 16.

Answer 2

To determine the total number of sigma bonds in P₄O₁₀, we need to understand its structure.

The structure of P₄O₁₀ consists of a cage-like structure with four phosphorus atoms and ten oxygen atoms. Each phosphorus atom is bonded to four oxygen atoms. Six oxygen atoms bridge the phosphorus atoms, and four oxygen atoms are terminal, bonded to individual phosphorus atoms via a double bond.

Here's a breakdown of the bonds:

• Each of the 4 phosphorus atoms is bonded to 4 oxygen atoms.
• Each P atom is bonded to 3 bridging O atoms and 1 terminal O atom.
• The 6 bridging oxygen atoms form P-O-P bonds.
• The 4 terminal oxygen atoms form P=O bonds (one sigma and one pi bond).

Counting the sigma bonds:

• 6 P-O-P bonds (6 sigma bonds)
• 4 P=O bonds (4 sigma bonds)
• Each of the 4 P atoms also has 3 other P-O sigma bonds, so 4 * 3 = 12 P-O bonds. However, each of these bonds is shared with another P atom, so there are 6 bridging P-O bonds.
• 4 P=O double bonds, which have 4 sigma bonds.

Therefore, the total number of sigma bonds is 6 (bridging P-O) + 4 (terminal P=O) + 6 (from the other P-O bonds) = 16 sigma bonds.

The total number of sigma bonds is:

6 (P-O-P) + 4 (P=O) + 6(P-O) = 16

The correct answer is: Option C: 16