Predict the chemical formulas of the ionic compound formed by (a) Fe3+ and OH-

Verified step by step guidance

1. Identify the charges of the ions involved: Fe^{3+} has a charge of +3 and OH^{-} has a charge of -1.
2. To form a neutral ionic compound, the total positive charge must balance the total negative charge.
3. Determine the ratio of ions needed to balance the charges. Since Fe^{3+} has a +3 charge and OH^{-} has a -1 charge, you will need three OH^{-} ions to balance one Fe^{3+} ion.
4. Write the chemical formula by placing the cation first followed by the anion, using subscripts to indicate the number of each ion needed. The formula will be Fe(OH)_{3}.
5. Ensure the compound is electrically neutral: 1(3+) + 3(-1) = 0, confirming the formula Fe(OH)_{3} is correct.

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 ions involved is crucial for predicting the correct formula of the resulting ionic compound.

Charge Balance

In ionic compounds, the total positive charge must balance the total negative charge to achieve electrical neutrality. For example, if a cation has a charge of +3 (like Fe3+) and the anion has a charge of -1 (like OH-), multiple anions are needed to balance the charge. This principle is essential for determining the correct ratio of ions in the compound's formula.

Chemical Formula Representation

The chemical formula of an ionic compound indicates the types and ratios of ions present. It is typically written with the cation first followed by the anion. For example, in the case of Fe3+ and OH-, the formula is derived by ensuring the charges balance, leading to the formula Fe(OH)3, which reflects the presence of one Fe3+ ion and three OH- ions.