Hydrates are chemical compounds made up of a salt and water. In other words, they are molecules in which water is combined with other substances. It’s important for students to understand hydrates and their properties, as well as how to identify different types of hydrates. Here are some examples of hydrates and how to teach them to students.
Firstly, it’s important to understand how hydrates work. Hydrates have a specific amount of water molecules attached to the salt, which is called the stoichiometry. This means that hydrates have a specific chemical formula depending on how many water molecules are attached to the salt. For example, copper sulfate pentahydrate has the chemical formula CuSO4 • 5H2O, which means that there are five water molecules attached to each copper sulfate molecule.
To help students understand hydrates, it’s helpful to use examples in real-life scenarios. Some examples of hydrates include magnesium sulfate heptahydrate (MgSO4 • 7H2O), which is commonly used in bath salts, and baking soda (NaHCO3 • H2O), which is used as a leavening agent in baking. Another example is blue vitriol (CuSO4 • 5H2O), which is used as a fungicide and is added to animal feed to increase copper levels.
To discuss each of these examples, students can research how each hydrate is used in industry and everyday life. They can also calculate the stoichiometry of each example to better understand how many water molecules are attached to each salt molecule. This will help them understand how each hydrate is formed and why it has certain properties.
Students can also perform experiments to further understand hydrates. For example, they can heat a hydrate to remove the water molecules and then weigh the hydrated vs. the anhydrous (water-free) compound to observe the mass difference. This will help students see how the water molecules affect the mass and structure of the compound.
Overall, hydrates may seem like a complex topic, but by using real-life examples, stoichiometry calculations, and experiments, students can grasp the concept and understand the importance of hydrates in everyday life.
