Predict the formula of the ionic compound that forms between potassium and sulfur. (LO 6.11) (a) KS (b) KS₂ (c) K₂S₂ (d) K₂S

Verified step by step guidance

1. Identify the charges of the ions formed by potassium and sulfur. Potassium (K) typically forms a +1 cation (K⁺), and sulfur (S) typically forms a -2 anion (S^2-).
2. Use the crisscross method to balance the charges of the ions. The absolute value of the charge of each ion becomes the subscript of the other ion.
3. Write the formula by placing the cation first and the anion second, ensuring that the subscripts are in the lowest whole number ratio and are written as simple integers.
4. Check if the total charges from the cations and anions balance to zero, confirming the compound is electrically neutral.
5. The resulting formula should reflect a balance where the total positive charge from potassium equals the total negative charge from sulfur.

Key Concepts

Ionic Compounds

Ionic compounds are formed when atoms transfer electrons, resulting in the formation of positively charged cations and negatively charged anions. The electrostatic attraction between these oppositely charged ions leads to the creation of a stable compound. Understanding the charges of the involved ions is crucial for predicting the correct formula of the ionic compound.

Valency and Charge of Ions

The valency of an element indicates its ability to combine with other elements, often determined by the number of electrons in its outer shell. Potassium (K) has a valency of +1, while sulfur (S) has a valency of -2. This difference in valency is essential for determining the ratio of ions in the resulting ionic compound.

Chemical Formula Representation

The chemical formula of an ionic compound reflects the ratio of the constituent ions. For potassium and sulfur, the correct formula must balance the total positive and negative charges. This involves using subscripts to indicate the number of each type of ion, ensuring that the overall charge of the compound is neutral.