1.Name the ionic compound MgCl2. Spell out the full name of the ionic compound. If the metal in the ionic compound is a transition element (with variable charge metal ions), the ionic charge is written as a Roman numeral following the element name of the cation. 2. Name the ionic compound CuF2. Spell out the full name of the ionic compound. 3.Name the ionic compound CuNO3. Spell out the full name of the ionic compound.
The Correct Answer and Explanation is:
Correct Answers:
- MgCl₂ — Magnesium chloride
- CuF₂ — Copper(II) fluoride
- CuNO₃ — Copper(I) nitrate
Explanation
Ionic compounds are named based on specific rules established by IUPAC (International Union of Pure and Applied Chemistry). The name consists of the cation (metal) followed by the anion (non-metal or polyatomic ion).
1. MgCl₂ – Magnesium chloride
Magnesium (Mg) is an alkaline earth metal in Group 2 of the periodic table. It has a fixed charge of +2 and does not require a Roman numeral in its name. Chlorine (Cl) is a halogen and gains one electron to become Cl⁻. Since two Cl⁻ ions are needed to balance one Mg²⁺, the formula is MgCl₂. The name is simply magnesium chloride — no Roman numeral is needed because magnesium’s charge is always +2.
2. CuF₂ – Copper(II) fluoride
Copper (Cu) is a transition metal, meaning it can have multiple oxidation states (commonly +1 and +2). Fluoride (F⁻) is a monatomic anion with a -1 charge. Since there are two F⁻ ions, the total negative charge is -2, so copper must be +2 in this compound. Thus, we write the name as Copper(II) fluoride. The Roman numeral (II) indicates the +2 charge on the copper ion.
3. CuNO₃ – Copper(I) nitrate
Nitrate (NO₃⁻) is a polyatomic ion with a charge of -1. Since there is only one nitrate ion, copper must have a +1 charge to balance the charge. Therefore, the correct name is Copper(I) nitrate, where the Roman numeral (I) represents the +1 oxidation state of copper.
Summary:
- Use Roman numerals for transition metals with variable charges.
- Don’t use Roman numerals for main group metals with fixed charges.
- Match the total positive and negative charges to ensure compound neutrality.
