What are chemical properties

Chemical Property Definition and Examples

Learn About Chemical Properties of Matter

A chemical property is a characteristic or behavior of a substance that may be observed when it undergoes a chemical change or reaction. Chemical properties are seen either during or following a reaction since the arrangement of atoms within a sample must be disrupted for the property to be investigated. This is different from a physical property, which is a characteristic that may be observed and measured without changing the chemical identity of a specimen.

Key Takeaways: Chemical Property

Examples of Chemical Properties

Examples of chemical properties of a substance can include:

Remember, a chemical change must occur for a chemical property to be observed and measured. For example, iron oxidizes and becomes rust. Rusting is not a property that can be described based on analysis of the pure element.

Uses of Chemical Properties

Chemical properties are of great interest to materials science. These characteristics help scientists classify samples, identify unknown materials, and purify substances. Knowing the properties helps chemists make predictions about the type of reactions to expect. Because chemical properties are not readily apparent, they are included in labels for chemical containers. Hazard labels based on chemical properties should be affixed to containers, while full documentation should be maintained for easy reference.

What is physical properties?

Physical properties are those that can be observed and measured without changing the actual composition of the matter. The chemical and molecular composition remains the same regardless of the measurement method that is used.

Any property that can be detected and measured without performing a chemical reaction is thus a physical property.

Physical changes can occur, e.g. change of states, but this only changes the physical shape not the chemical structure or molecular composition of the substance. For instance, when water freezes, the chemical nature of the water does not change, so freezing point is another physical property.

States of matter is also a physical property since all substances can exist in a solid, liquid or gas phase depending on energy loss or gain.

The same element is present after the change and throughout the process. Physical changes are related to physical properties.

Physical properties can be extensive or intensive:

Extensive properties are external, that is the substance can’t be identified using these and the value changes depending on the amount of the substance present. For example you can measure 10g of oil or 10g of water but this doesn’t enable you to identify a substance as being oil or water.

Intensive properties are always the same and can be used to identify what a substance is. E.g. density of liquid water is 1g/ml, boiling point is 100 o C and freezing point is 0 o C.

Using multiple intensive properties together allows one to identify a substance. Substances can also be classified and grouped based on their physical properties.

Examples of physical properties include:

What is chemical properties?

A chemical property by definition means that measuring the property leads to a change in the actual chemical structure of the substance. Chemical properties become apparent when the substance undergoes a chemical change or reaction.

Chemical properties describe the ability of a substance to combine with other substances, or change into a different product. It is a way to describe what a substance could react with or end up changing into. When a chemical reaction occurs, matter changes to an entirely different type of matter.

For instance sodium can react with water vapor in the air and violently explode; iron and oxygen combine to form rust so iron has the chemical ability to form rust; gasoline has the ability to burn (it is flammable).

A chemical property is any quality that can be established only when a change is made in the chemical identity of the substance. Simply touching or observing a substance will not demonstrate its chemical properties. The structure of the matter or substance has to be changed in order to see the chemical property.

Chemical properties are useful to know since this helps in the identification of unknown substances or when trying to separate or purify substances, and can enable scientists to classify substances such as compounds.

Knowing these properties, scientists can come up with applications where various substances can be used.

Scientists are also able to predict how samples will react in a chemical reaction if they have prior knowledge of the substances’ chemical properties.

Some examples of chemical properties include the following:

What is the difference between physical and chemical properties?

causing or resulting in a change in the matter, while chemical properties are only observed after a change in the matter has occurred.

Examples of Chemical Properties

Chemical properties and physical properties are characteristics of matter that can be used to help identify and describe it. Chemical properties are those that you can observe only if matter experiences a chemical change or chemical reaction. In other words, you need to change the chemical identity of a sample in order to observe and measure its chemical properties.

Why Is It Important to Know the Chemical Properties of a Sample?

» data-caption=»» data-expand=»300″ data-tracking-container=»true» />

Simon McGill/Getty Images

It’s important to know the chemical properties of a sample because this information can be used to:

Let’s take a closer look at some examples of chemical properties.

Toxicity as a Chemical Property

» data-caption=»» data-expand=»300″ data-tracking-container=»true» />

Adam Gault/Getty Images

Toxicity is an example of a chemical property. Toxicity is how dangerous a chemical is to your health, a particular organ, another organism, or to the environment. You can’t tell by looking at a chemical whether or not it is toxic. How poisonous a substance is depends on the situation, so this is a property that can only be observed and measured by exposing an organic system to a sample. The exposure causes a chemical reaction or set of reactions. The net result of the chemical changes is the toxicity.

Flammability as a Chemical Property

» data-caption=»» data-expand=»300″ data-tracking-container=»true» />

Flammability is a measure of how readily a sample ignites or how well it can sustain a combustion reaction. You don’t know how easily something will burn until you try to ignite it, so flammability is an example of a chemical property.

Chemical Stability

» data-caption=»» data-expand=»300″ data-tracking-container=»true» />

The Colombian Way Ltda/Getty Images

Chemical stability is also known as thermodynamic stability. It occurs when a substance is at chemical equilibrium in its environment, which is its lowest energy state. This is a property of matter that is determined by its specific conditions, so it can’t be observed without exposing a sample to that situation. Thus, chemical stability fits the definition of a chemical property of matter.

Chemical stability is related to chemical reactivity. While chemical stability pertains to a given set of circumstances, reactivity is a measure of how likely a sample is to participate in a chemical reaction under a variety of conditions and how quickly a reaction might proceed.

Oxidation States or Oxidation Number

» data-caption=»Transition metal solutions display vivid colors because of their oxidation states» data-expand=»300″ data-tracking-container=»true» />

Difference Between Physical and Chemical Properties

How to Tell Them Apart and Examples of Each

Siede Preis/Getty Images

Measurable characteristics of matter may be categorized as either chemical or physical properties. What is the difference between a chemical property and a physical property? The answer has to do with chemical and physical changes of matter.

A Physical Property

A physical property is an aspect of matter that can be observed or measured without changing its chemical composition. Examples of physical properties include color, molecular weight, and volume.

A Chemical Property

A chemical property may only be observed by changing the chemical identity of a substance. In other words, the only way to observe a chemical property is by performing a chemical reaction. This property measures the potential for undergoing a chemical change. Examples of chemical properties include reactivity, flammability and oxidation states.

Telling Physical and Chemical Properties Apart

Sometimes it can be tricky to know whether or not a chemical reaction has occurred. For example, when you melt ice into water, you can write the process in terms of a chemical reaction. However, the chemical formula on both sides of the reaction is the same. Since the chemical identity of the matter in question is unchanged, this process represents a physical change.

Thus melting point is a physical property. On the other hand, flammability is a chemical property of matter because the only way to know how readily a substance ignites is to burn it. In the chemical reaction for combustion, the reactants and products are different.

Look for Tell-Tale Signs of a Chemical Change

Usually, you don’t have the chemical reaction for a process. You can look for tell-tale signs of a chemical change. These include bubbling, color change, temperature change, and precipitation formation. If you see signs of a chemical reaction, the characteristic you are measuring is most likely a chemical property. If these signs are absent, the characteristic is probably a physical property.

What are chemical properties

What are Chemical Properties and Changes?

Chemical properties of matter describes its «potential» to undergo some chemical change or reaction by virtue of its composition. What elements, electrons, and bonding are present to give the potential for chemical change.

It is quite difficult to define a chemical property without using the word «change». Eventually you should be able to look at the formula of a compound and state some chemical property. At this time this is very difficult to do and you are not expected to be able to do it.

For example hydrogen has the potential to ignite and explode given the right conditions. This is a chemical property.

Metals in general have they chemical property of reacting with an acid. Zinc reacts with hydrochloric acid to produce hydrogen gas. This is a chemical property.

Click for larger image

Chemical Changes or Reactions:

Chemical change results in one or more substances of entirely different composition from the original substances. The elements and/or compounds at the start of the reaction are rearranged into new product compounds or elements.

A CHEMICAL CHANGE alters the composition of the original matter. Different elements or compounds are present at the end of the chemical change. The atoms in compounds are rearranged to make new and different compounds.

Magnesium reacts with oxygen from the air producing an extremely bright flame. This is a chemical change since magnesium oxide has completely different properties than magnesium metal shown on the left. Safety: Do not try this without supervision and DO NOT LOOK DIRECTLY AT THE LIGHT!

For example iron has the potential to rust given the right conditions. This is a chemical property.

If iron does rust, this is a slow chemical change since rust is an iron oxide with different properties than iron metal.

In the graphic on the left, iron or steel wool is burning in a fast reaction with oxygen as contrasted with the slow rusting of iron also with oxygen.

In the element iron only atoms of iron are in contact with each other. In the element oxygen each oxygen is joined with one other to make a diatomic molecule. These atoms and molecules are rearranged so that two iron atoms combine with three atoms of oxygen to form a new compound.

Click for larger image

The reactions in both of the (left and lower) cases start when a solid tablet is dropped into water. The chemicals in dry solid form must dissolve in the water before a reaction may take place. In both cases gas bubbles are observed. This is an initial chemical reaction. A flaming or glowing splint is used to test for the identity of the gases by using their chemical properties.

QUES.: Define chemical property. Then use this definition to describe the behavior toward the flaming splint for carbon dioxide in the example on the left.

Answer: A chemical property defines whether a chemical reaction will or will not take place. Because the flame goes out, this shows that the chemical property of carbon dioxide gas is that no combustion reaction can take place in its presence.

Click for larger image

The reactions in both of the (left and upper) cases start when a solid tablet is dropped into water. The chemicals in dry solid form must dissolve in the water before a reaction may take place. In both cases gas bubbles are observed. A flaming or glowing splint is used to test for the identity of the gases.

QUES.: Define chemical property. Then use this definition to describe the difference in behavior toward the flaming splint for both gases in the above examples.

Click for larger image

Zinc and Iodine Reaction

The reaction between the two elements to produce zinc iodide is very exothermic. Some of the unreacted iodine solid is heated to a gaseous iodine which is purple in color.

QUES.: A molecule is only defined as the simplest part of a compound with two or more atoms. (True or False)

QUES.: For an exothermic reaction, heat is given off in the process. (True or False)

QUES.: The fact that unreacted iodine changes to gaseous iodine is a: chemical or physical change?