Which of the following is the correct chemical formula for bromine pentachloride?

• A. BrCl3
• B. BrCl5
• C. Br5Cl
• D. Br2Cl5

Answer: (B)

Verified step by step guidance

1. Understand the naming convention for binary molecular compounds: the prefix 'penta-' means five, indicating the number of chlorine atoms bonded to bromine.
2. Identify the central atom and the number of atoms attached: 'bromine pentachloride' means one bromine atom bonded to five chlorine atoms.
3. Write the chemical formula by placing the symbol for bromine (Br) first, followed by the symbol for chlorine (Cl) with the subscript 5 to indicate five chlorine atoms.
4. Verify that the formula matches the name: BrCl5 corresponds to bromine pentachloride, where 'penta-' correctly indicates five chlorine atoms.
5. Confirm that other options do not match the name: BrCl3 has three chlorines, Br5Cl has five bromines, and Br2Cl5 has two bromines, so these are incorrect.