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Understanding chemical properties is key to predicting how substances will behave under certain conditions. A chemical property is a characteristic of a material that becomes evident during or after a chemical reaction. It is inherently linked to the molecular structure and composition of the substance. For instance, the ability of iron to rust is a good example of a chemical property. When iron is exposed to oxygen and moisture, it undergoes a chemical change resulting in the formation of iron oxide, or rust.

Such properties are crucial since they determine the uses and limitations of a material in different applications. For example, knowing that a metal is prone to corrosion tells engineers they might need to treat it or use it in an environment where it won't react with oxygen.

A physical property, in contrast, is observable or measurable without altering the substance's chemical identity. Characteristics such as color, density, volume, and in the case of the textbook exercise, the boiling point of ethyl alcohol and the temperature at which dry ice vaporizes, are all physical properties. These properties are typically easy to observe and can often be quantified with the help of simple measurements.

It's important to mention that melting and boiling points are especially useful physical properties, as they help to identify a substance. They are also foldable: when you heat water, it boils at 100°C, but it's still the same water before and after boiling; no new substance is created.

A phase change is a transition between different states of matter: solid, liquid, and gas. This is featured in the exercise when dry ice sublimates, moving from a solid to a gaseous state without becoming a liquid in-between. It's fascinating to observe, as dry ice seems to 'vanish' into thin air.

Understanding phase changes is essential, not only for scientific purposes but also in practical applications like refrigeration and in creating the 'fog effect' in theaters. Phase changes are physical changes that occur under specific temperatures and pressures, and knowing the conditions for these changes helps us to harness them for use in everyday technology.

A chemical reaction is a process by which one or more substances are transformed into different substances. This involves making and breaking chemical bonds, leading to substances with new properties. For example, the rusting of iron, mentioned in the exercise, is a chemical reaction wherein iron combines with oxygen in the presence of water to produce iron oxide.

Every chemical reaction is characterized by a change in properties and energy. These reactions are central to all biological and technological processes. From digesting food to powering cars, chemical reactions shape our world. They're so ubiquitous that sometimes we forget even cooking is a series of chemical reactions.