What is the name of the following chemical compound: B2Br2

What is the name of the following chemical compound: B2Br2? A. boron bromide B. boron tetrabromide C. diboron bromide D. diboron tetrabromide E. diboron tetrabromine

The correct answer and explanation is:

The correct answer is: D. diboron tetrabromide

Explanation:

The chemical formula given is B₂Br₂. To name this compound correctly, we need to understand the rules for naming binary molecular compounds (compounds composed of two nonmetals).

1. Identify the elements and their quantities:
   • B = boron
   • Br = bromine (in compounds, called bromide when as an anion or in naming)
   The formula shows 2 boron atoms and 2 bromine atoms.
2. Use Greek prefixes to indicate the number of atoms:
   • Mono- = 1 (usually omitted for the first element)
   • Di- = 2
   • Tri- = 3
   • Tetra- = 4, etc.
3. Naming each element:
   • The first element is named using the element name itself: “boron”
   • The second element uses the root of the element name plus the suffix “-ide”: “bromide”
4. Apply prefixes according to the number of atoms:
   • Since there are 2 boron atoms, prefix “di-” is used → diboron
   • Since there are 2 bromine atoms, prefix “di-” is used → dibromide
5. Putting it together:
   • The name would be “diboron dibromide”
   • However, the compound is written as B₂Br₂, but the options given do not have “diboron dibromide”.
   • Instead, option D is “diboron tetrabromide” which suggests 4 bromine atoms.
6. Re-examining the formula:
   • If the compound were B₂Br₄, the name would be “diboron tetrabromide”.
   • For B₂Br₂, the name should be “diboron dibromide.”
7. Assessing the options: Option Meaning Matches B₂Br₂? A. boron bromide Boron + bromide (no prefix) Implies 1:1, BBr B. boron tetrabromide Boron + 4 bromines BBr₄, no “di” for boron C. diboron bromide 2 borons + 1 bromide B₂Br (not B₂Br₂) D. diboron tetrabromide 2 borons + 4 bromines B₂Br₄ E. diboron tetrabromine Incorrect suffix (“bromine”) Not used in nomenclature

None of these exactly matches B₂Br₂ except “diboron dibromide,” which is missing.

However, among the options, D “diboron tetrabromide” is the closest and commonly known compound is B₂Br₄ (diboron tetrabromide).

Additional Notes:

• The formula B₂Br₂ is unusual because boron typically forms compounds such as BBr₃ (boron tribromide) or B₂Br₄ (diboron tetrabromide).
• If the formula were B₂Br₄, the correct name would be “diboron tetrabromide” (Option D).
• If it’s strictly B₂Br₂, the name would be “diboron dibromide” which is not listed.

Therefore, based on the provided choices and common compounds, the best fit is Option D: diboron tetrabromide.

Summary:

• The prefixes “di-” and “tetra-” indicate the number of atoms.
• The second element is named with “-ide” ending.
• Boron bromide compounds usually have formulas like BBr₃ or B₂Br₄.
• “Diboron tetrabromide” corresponds to B₂Br₄.
• Since B₂Br₂ is uncommon and no “diboron dibromide” is offered, Option D is the most reasonable choice.