Chapter 8: Problem 32
For each of the following pairs of elements, state whether the binary compound they form is likely to be ionic or covalent. Write the empirical formula and name of the compound: (a) I and Cl, (b) \(\mathrm{Mg}\) and \(\mathrm{F}\).
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Ionic Bonds
This exchange of electrons results in a strong attraction between the positively and negatively charged ions, forming an ionic bond.
Ionic compounds generally have high melting and boiling points because of these strong attractions. For instance, in the formation of magnesium fluoride, an electron from magnesium is transferred to fluorine. Magnesium becomes a cation (\(\text{Mg}^{2+}\)), and fluorine becomes an anion (\(\text{F}^{-}\)). Together, they form the compound \(\text{MgF}_2\), which is stable and neutral in charge.
Covalent Bonds
During covalent bond formation, atoms share specific pairs of electrons, effectively holding them together. For example, a covalent compound like iodine monochloride (\(\text{ICl}\)) forms when iodine and chlorine, both nonmetals, share one pair of electrons.
Covalent bonds can be single, double, or triple, depending on the number of shared electrons. This sharing leads to the formation of molecules with specific shapes and angles, contributing to the diverse physical properties of covalent compounds. Some common properties include lower melting and boiling points compared to ionic compounds, and they do not conduct electricity in the solid state.
Empirical Formulas
An empirical formula provides a basic understanding of the proportion of each element in a compound. For instance, \(\text{MgF}_2\) is the empirical formula for magnesium fluoride, showing a 1:2 ratio of magnesium to fluorine.
In covalent compounds like iodine monochloride, their empirical formula is often the same as their molecular formula because covalent compounds often involve simple ratios. Understanding these formulas helps in predicting how elements combine and what kinds of compounds they form, based on their ratios.
Naming Compounds
For ionic compounds, names are straightforward. The metal (cation) is named first, followed by the nonmetal (anion) with an "ide" ending. For example, \(\text{MgF}_2\) is named magnesium fluoride. The name indicates the presence of a magnesium ion and fluoride ions in the compound.
Covalent compounds use a different system involving prefixes to indicate the number of each type of atom present. Common prefixes include mono-, di-, and tri-. In \(\text{ICl}\), the name is iodine monochloride, where "mono-" signifies one chlorine atom bonded with iodine. Naming rules provide consistency and understanding when discussing and researching chemical compounds.