What is the name of the following ionic compound: (NH4)20
The Correct Answer and Explanation is:
The compound (NH₄)₂O is named ammonium oxide.
Explanation:
To understand this compound, let’s break down the formula:
- (NH₄)₂O consists of two ammonium ions (NH₄⁺) and one oxide ion (O²⁻).
- Ammonium Ion (NH₄⁺):
- The ammonium ion is a polyatomic ion with the formula NH₄⁺. It consists of one nitrogen atom (N) bonded to four hydrogen atoms (H), and it carries a positive charge (+1). The ammonium ion is often formed when ammonia (NH₃) accepts a proton (H⁺) from an acid.
- Oxide Ion (O²⁻):
- The oxide ion is a negatively charged ion (anion) formed when oxygen (O) gains two electrons, giving it a charge of -2. Oxide ions are typically found in compounds where oxygen is in its highest oxidation state.
Naming the Compound:
- When naming ionic compounds, the cation (positive ion) is named first, followed by the anion (negative ion).
- In (NH₄)₂O, the cation is ammonium (NH₄⁺), and the anion is oxide (O²⁻).
- Since ammonium is a polyatomic ion, it keeps its name unchanged. The oxide ion simply retains its name as well.
- The subscript 2 after ammonium indicates that there are two ammonium ions in the formula.
- Therefore, the compound is named ammonium oxide.
Formula Verification:
To confirm the formula, note that each ammonium ion has a charge of +1, and the oxide ion has a charge of -2. To balance the charges, two ammonium ions (2 × +1 = +2) are required to balance one oxide ion (-2), resulting in the formula (NH₄)₂O.
Thus, ammonium oxide is the correct name for the ionic compound with the formula (NH₄)₂O.