Chapter 2: Problem 51
What is an ionic compound? How is electrical neutrality maintained in an ionic compound?
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Electrical Neutrality
For a compound to be electrically neutral, the total positive charge from the cations must equal the total negative charge from the anions. This balance is essential to the stability and formation of ionic compounds.
- If you have one sodium ion ( ext{Na}^+) and one chloride ion ( ext{Cl}^-), their charges are equal but opposite, leading to a neutral compound, sodium chloride.
- The chemical formula, such as ext{NaCl}, indicates the precise ratio of ions needed to maintain electrical neutrality.
Cation and Anion Formation
Cations are formed when metals lose electrons. This loss means the metal atom achieves a stable electron configuration and becomes positively charged. For instance, sodium ( ext{Na}) will lose one electron to form a sodium cation ( ext{Na}^+).
Anions, on the other hand, form when non-metals gain electrons. By acquiring extra electrons, non-metals fill their outermost electron shells, attaining stability and a negative charge. A chlorine atom ( ext{Cl}) gains one electron to become a chloride anion ( ext{Cl}^-).
- Cation: Metal losing electron (e.g., ext{Na} ightarrow ext{Na}^+ + e^-)
- Anion: Non-metal gaining electron (e.g., ext{Cl} + e^- ightarrow ext{Cl}^-)
Chemical Formula
When you look at a chemical formula, such as ext{NaCl}, it tells us that sodium and chlorine combine in a 1:1 ratio to form sodium chloride. This ratio ensures the charges from the cations and anions cancel each other out. In more complex ionic compounds, such as calcium chloride (CaCl₂), the formula indicates that one calcium ion ( ext{Ca}^{2+}), with its 2+ charge, balances with two chloride ions ( ext{Cl}^-), each with a 1- charge.
- Simple ratio: ext{NaCl} (1:1)
- Complex ratio: ext{CaCl₂} (1:2)
Metal and Non-Metal Composition
Metals are located on the left side of the periodic table and have a tendency to lose electrons, forming cations. Non-metals, which are found on the right side of the periodic table (excluding noble gases), generally gain electrons, forming anions.
- Metal: Electron donor (e.g., Sodium)
- Non-Metal: Electron acceptor (e.g., Chloride)