Question

which of the following is the correct nomenclature for $\ce{al_{2}o_{3}}$?
\bigcirc aluminum oxide
\bigcirc aluminum trioxide
\bigcirc aluminum ii oxide
\bigcirc aluminum iii oxide

Explanation:

Step1: Recall Ionic Compound Nomenclature

For ionic compounds with a metal (like Al) and a non - metal (like O), when the metal has a fixed oxidation state (Al always has +3 in compounds with O), we use the name of the metal followed by the name of the non - metal with its ending changed to -ide.

Step2: Analyze the Formula \(Al_2O_3\)

Aluminum (Al) has a +3 oxidation state and oxygen (O) has a -2 oxidation state. The formula is formed by the criss - cross method (\(2\times(+3)+3\times(-2)=0\)). Since aluminum has a fixed oxidation state here, we name it by the metal name (aluminum) and the non - metal name with -ide (oxide).

• "Aluminium trioxide" is incorrect because we don't use prefixes for ionic compounds with metals of fixed oxidation states in this way.
• "Aluminum II Oxide" and "Aluminum III Oxide" are incorrect because aluminum has a fixed oxidation state of +3 in this compound, and we don't need to use Roman numerals (Roman numerals are used for metals with variable oxidation states).
• "Aluminum Oxide" is correct as it follows the ionic compound nomenclature for a metal with a fixed oxidation state.

Answer:

A. Aluminum Oxide