Assume that you were given samples of two white, crystalline compounds, one of them ionic and one covalent. Describe how you might tell which is which.
I just can't seem to figure out, can you please help. Thanks.
Try dissolving them in water and hexane.
increase the temperature, the first one to melt is the covalent
To determine whether a compound is ionic or covalent, you can use several methods:
1. Solubility: Test the compounds' solubility in water or common solvents. Ionic compounds tend to be soluble in water and other polar solvents, while covalent compounds are generally insoluble in water but can dissolve in non-polar solvents like acetone or hexane.
2. Conductivity: Dissolve a small amount of each compound in water and test their conductivity using a conductivity meter. Ionic compounds usually conduct electricity when dissolved in water due to the presence of free ions, whereas covalent compounds do not conduct electricity in either the solid or dissolved form.
3. Melting and boiling points: Ionic compounds typically have high melting and boiling points due to the strong electrostatic interactions between the ions in the crystal lattice. Covalent compounds generally have lower melting and boiling points because of weaker intermolecular forces.
4. Crystal shape and structure: Examine the crystals under a microscope. Ionic compounds tend to form well-defined, geometric-shaped crystals, while covalent compounds can have irregular or amorphous crystal structures.
5. Formula and name: Analyze the chemical formula and name of each compound. Ionic compounds are typically composed of a metal cation and a non-metal anion, and their names often end in "-ide" or "-ate." Covalent compounds are usually composed of non-metal elements and have prefixes in their names indicating the number of atoms involved.
Remember, these methods can provide clues, but they may not always give a definitive answer. It is best to use a combination of techniques to confirm the nature of the compounds.
To determine whether a given compound is ionic or covalent based on samples, you can make use of several methods. Here is a simple step-by-step process to help you identify which compound is ionic and which is covalent:
1. Solubility: Begin by testing the solubility of each compound in water. Ionic compounds tend to be soluble in water due to their ability to dissociate into ions, while covalent compounds are typically insoluble or only slightly soluble. If one of the compounds dissolves readily in water, it is likely ionic.
2. Conductivity: Dissolve a small amount of each compound in water and test their conductivity using a conductivity apparatus. Ionic compounds conduct electricity when dissolved in water due to the presence of free-moving ions, whereas covalent compounds do not conduct electricity because they do not produce free ions. If one of the compounds exhibits conductivity, it suggests that it is ionic.
3. Melting point: Compare the melting points of the two compounds. Ionic compounds usually have high melting points due to the strong electrostatic attractions between ions, while covalent compounds tend to have lower melting points due to weaker intermolecular forces. If one of the compounds has a significantly higher melting point, it is likely to be ionic.
4. Formula: Examine the chemical formula of each compound. Ionic compounds consist of a metal cation and a non-metal anion, while covalent compounds consist of non-metal elements only. If one of the compounds contains a metal, it is likely to be ionic.
By systematically evaluating the solubility, conductivity, melting point, and formula of each compound, you should be able to determine which compound is ionic and which one is covalent.