Identify the components of the ionic formula based on the name nickel (III) sulfide.
What is the symbol for the element that forms the positive cation?
What is the symbol for the element that forms the negative anion?
What is the subscript on the cation in the neutral formula?
What is the subscript on the anion in the neutral formula?
The Correct Answer and Explanation is :
The compound in question is nickel(III) sulfide, which consists of two components: a positively charged cation (nickel) and a negatively charged anion (sulfide). To break down this formula, we first need to understand the ions involved and how they combine to form a neutral compound.
1. Symbol for the element that forms the positive cation:
The element that forms the positive cation in nickel(III) sulfide is Nickel (Ni). Nickel typically forms a cation by losing electrons. In this case, the Roman numeral (III) in the name indicates that nickel has a charge of +3, meaning it has lost three electrons.
2. Symbol for the element that forms the negative anion:
The anion in this compound is derived from Sulfur (S), which forms the sulfide ion (S²⁻). Sulfur typically gains two electrons to achieve a stable electron configuration, resulting in a charge of -2.
3. Subscript on the cation in the neutral formula:
To achieve electrical neutrality, the total positive charge must balance the total negative charge in the compound. The nickel cation has a charge of +3, while the sulfide anion has a charge of -2. To balance the charges, we need two nickel ions (Ni³⁺) for every three sulfide ions (S²⁻). The subscript on the nickel cation is therefore 2.
4. Subscript on the anion in the neutral formula:
Similarly, the subscript on the sulfide anion is 3. This is because three sulfide ions (each with a charge of -2) will balance the charge of the two nickel ions (each with a charge of +3).
Conclusion:
The correct ionic formula for nickel(III) sulfide is Ni₂S₃, which represents two nickel cations and three sulfide anions. This formula reflects the need to balance the charges between the cations and anions to form a neutral compound. The process of balancing charges ensures that the ionic compound is stable and neutral overall.