A hydrate is a substance where in it contains water and other constituent elements. To know whether if that compound was a hydrate,you should record its mass, then put it in a test tube and heat it with a Bunsen burner. If the compound is a hydrate, the water in the compound will discharge in the form of water vapor. At the next 5-10 minutes, remove it in the test tube and weigh it up again. If the mass is now fewer, that means that there was water existing that has now evaporated, and the compound was a hydrate.
All solutions are mixtures of two or more substances, but unless the mixture has a homogeneous distribution of solutes in the solvent, then the mixture is not a solution. Therefore, all mixtures are not solutions.
If you clear volume in the density equation:

The greater the density the lower the volume. This means, the volume of gold nugget will be smaller than the volume of iron pyrite nugget.

Answer:
The majority of chemical processes are reactions that occur in solution. Important industrial processes often utilize solution chemistry. "Life" is the sum of a series of complex processes occurring in solution. Air, tap water, tincture of iodine, beverages, and household ammonia are common examples of solutions.Turpentine as a solvent are used in the production of paints, inks and dyes. ↔Water as a solvent is used in the making of food, textiles, soaps and detergents. ↔Alloys are solid solutions that are used in the manufacture of cars, aerospace and other vehicles.Household cleaners like bleach are solutions, they help us to make our houses clean. Beverages such as fizzy drinks, mineral water and tea are solutions. In hydroponics, the roots of plants are immersed in solutions containing dissolved mineral salts.