According to standard nomenclature, what is the correct systematic name for the compound with formula PbO?

Introduction / Context:
Systematic nomenclature in inorganic chemistry is designed to provide clear information about the oxidation state of metals in compounds. Lead can exist in more than one oxidation state, most commonly plus two and plus four. The formula PbO indicates a particular ratio of lead to oxygen and therefore a particular oxidation state. This question asks you to choose the most appropriate systematic name for PbO, based on standard naming rules.

Given Data / Assumptions:

• The compound has the formula PbO.
• Oxygen usually has an oxidation state of minus two in binary oxides.
• Lead is a metal that can show oxidation states plus two and plus four.
• We use a naming system that clearly indicates the oxidation state of the metal.

Concept / Approach:
In PbO, oxygen contributes a total charge of minus two since there is one oxygen atom with oxidation state minus two. To balance this charge, lead must have an oxidation state of plus two. In the systematic naming convention, the metal name is followed by a Roman numeral in brackets indicating the oxidation state, or equivalently by a clear verbal description such as lead two oxide. Traditional names use plumbous for lead plus two and plumbic for lead plus four. Therefore, PbO is lead plus two oxide, sometimes called plumbous oxide, while lead plus four oxide or plumbic oxide would describe PbO2, not PbO.

Step-by-Step Solution:
Step 1: Assign the oxidation state of oxygen in PbO as minus two, based on its usual value in oxides. Step 2: Set up the total charge balance. Since the compound is neutral, the oxidation state of lead plus the oxidation state of oxygen must sum to zero. Step 3: Solve for the oxidation state of lead: x plus minus two equals zero, so x equals plus two. Step 4: Note that this oxidation state is represented in systematic naming by describing the compound as lead two oxide. Step 5: Reject names that correspond to lead plus four or that do not specify the oxidation state precisely for a metal with variable valency.

Verification / Alternative check:
As an alternative check, look at the formula for another common oxide of lead, PbO2. In that compound, two oxygen atoms provide a total of minus four charge, so lead must be plus four, and the compound is described as lead four oxide or plumbic oxide. This comparison clearly shows that plumbic oxide refers to PbO2, not PbO. Therefore, the compound PbO, with lead in the plus two state, is accurately named lead two oxide under the chosen naming convention.

Why Other Options Are Wrong:
Plumbic oxide and lead four oxide correspond to the oxide where lead is in the plus four oxidation state, that is PbO2, not PbO.
Lead oxide without specifying the oxidation state is ambiguous, because lead can form both PbO and PbO2, so this name is not fully systematic.
Lead dioxide is another common name associated with PbO2 rather than PbO and therefore does not describe the given formula correctly.

Common Pitfalls:
Students often choose general names that omit the oxidation state, leading to ambiguity whenever a metal forms more than one type of oxide. Another frequent error is mixing up plumbous and plumbic or confusing the formulae PbO and PbO2. A good strategy is always to calculate the oxidation state explicitly and then construct the name so that this value is clearly indicated. This habit helps avoid mistakes in questions involving variable valency metals.

Final Answer:
The correct systematic name for PbO, with lead in the plus two oxidation state, is lead two oxide.