Which of the following is the correct chemical formula for copper(I) iodide?

• A. Cu2I2
• B. CuI
• C. Cu2I
• D. CuI2

Answer: (B)

Verified step by step guidance

1. Identify the oxidation state of copper in copper(I) iodide. The Roman numeral I indicates that copper has a +1 charge (Cu⁺).
2. Determine the charge on the iodide ion. Iodide (I⁻) has a charge of -1.
3. Balance the charges to form a neutral compound. Since Cu⁺ and I⁻ have charges of equal magnitude but opposite sign, they combine in a 1:1 ratio.
4. Write the chemical formula by combining one Cu⁺ ion with one I⁻ ion, resulting in CuI.
5. Verify that the formula CuI is electrically neutral and correctly represents copper(I) iodide.