How to Tell if Something is a Physical or Chemical Property?

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If something is a physical property, it is possible to tell what it is by observation and without irreversibly changing the material that has the property. Chemical properties, on the other hand, are hidden. They can't be observed without performing chemical experiments that result in chemically changing the material. When the experiment is complete, it is clear whether the material has the chemical property that the experiment was designed to detect. The more physical and chemical properties you know, the easier it is to identify the material in question accurately.

Is Density a Physical or Chemical Property?

Density is a physical property. This is because it can be determined without performing chemical experiments. To find the density of a material, you have to know the volume and weight. The weight, in ounces or grams, can be found by weighing the material on a scale. The volume, in cubic inches or cubic centimeters, can be found by placing the material in a container filled with liquid and measuring the volume of the liquid that overflows. The resulting density is expressed in ounces per cubic inch or grams per cubic centimeter. For large materials, the corresponding density is expressed as pounds per cubic foot or kilograms per cubic meter. For liquids, density is described as pounds per gallon or kilograms per liter.

Is Solubility a Physical or Chemical Property?

Solubility is a physical property. The reason is because it can be determined by simple observation and does not change the chemical composition of the material. For example, when salt dissolves in water, it is still salt. Whether a material is soluble in a solvent or not can be found by placing a sample of the material in the solvent, stirring and checking if it dissolves. If the material is soluble, the solubility is the maximum amount of material that dissolves in a solvent at a given temperature. The units of solubility are grams per 100 grams of solvent, grams per liter or moles per liter.

Is Color a Physical or Chemical Property?

Color is a physical property. Why? Because determining the color of a material does not involve any chemical experiments or changes. Color is the result of some wavelengths of light being absorbed by the material and other wavelengths being reflected. For example, a material might absorb some green and blue light with the result that the material looks reddish. If it absorbs all shades equally, the material looks gray or black. If it reflects all light, it looks white. Color can help identify a material and, while it is a physical property, it can be used together with chemical experiments when the experiments produce a known material with a specific color.

Is Flammability a Chemical or Physical Property

Flammability is a chemical property. It involves chemical change. To determine whether a material is flammable, you test the material with heat. If it burns, the material undergoes a chemical reaction, demonstrating its flammability. Flammability testing is carried out on a small sample of the material, according to test protocols relevant to the type of flammability. For example, testing can be with an open flame applied beneath the sample, or the sample can be heated to see if it will burst into flame. Such tests can determine the combustion temperature, the heat of combustion, and the combustion byproducts as well as the flammability.

Is Melting Point a Physical or Chemical Property

Melting point is a physical property. Melting does not involve a chemical change. The melting point is the temperature at which a solid changes to a liquid. You can find it by heating a solid material and recording the temperature at which it melts. Typically, the temperature steadily rises until it reaches the melting point of the material. At this point, the temperature rises more slowly or even stops as the material absorbs the heat to produce the melting. When all the material has melted, the temperature continues to rise. In addition to the melting point, the heat of fusion for the material can be found if the heat added while the temperature remained steady is measured.

Is Boiling Point a Physical or Chemical Property

Boiling point is a physical property. Vaporization is a physical change of state that does not involve a chemical reaction. Heating a liquid until it vaporizes allows the determination of the boiling point of the material. When the liquid is heated steadily, the temperature of the liquid rises until it hits the boiling point. At the boiling point, the temperature stops increasing as the heat of vaporization is absorbed by the material and the liquid is changed to gas. If the gas is collected and condensed, it proves that the boiling point is, in fact, a physical property because the process can easily be reversed, and the original material can be recovered.

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About the Author

Bert Markgraf is a freelance writer with a strong science and engineering background. He has written for scientific publications such as the HVDC Newsletter and the Energy and Automation Journal. Online he has written extensively on science-related topics in math, physics, chemistry and biology and has been published on sites such as Digital Landing and Reference.com He holds a Bachelor of Science degree from McGill University.

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