Chemical Properties - Online Tutor, Practice Problems & Exam Prep

Chemical properties are observed during chemical reactions, where the identity of a substance changes. Key properties include flammability, toxicity, corrosion, reactivity, radioactivity, and solubility. Reactants undergo a transformation to produce new products, as illustrated by the reaction of methanol with oxygen to yield carbon dioxide and water. Understanding these properties is essential for grasping the nature of chemical changes and their implications in various contexts.

Chemical Properties Concept

So we've talked about matter and the different types of changes that it can undergo. We know that it can undergo physical and chemical changes with them being reversible or irreversible. Now, associated with these changes, we can talk about the properties that accompany them. Here we're taking a look at chemical properties. We're going to say that a chemical property is just a property of matter that is observed during a chemical reaction. Remember, a chemical reaction represents a chemical change where the composition and, therefore, the identity of a substance is forever altered. Now we're going to say here the matter will be changed into a new substance after the reaction. Here we have our chemical reaction. We have 2 CH3OH, and remember g here means gas. The name of this compound would be called methanol. It reacts with 3 oxygen gases. Remember before this arrow, so before the arrow, we say that these 2 compounds represent reactants. They undergo a chemical change to produce 2 CO2, so 2 carbon dioxide gases, plus four water vapors. Here after the arrows, remember we call these compounds after the arrows, products. So when we're talking about chemical properties, we must always keep in mind that it's related in some way to a chemical reaction where our reactant, our starting material, is changed chemically with its bonds and composition to help create something new. Now with chemical properties, we have certain types of properties that are key to remember. So if we take a look here, for the first one we have the image of a flame. So we're going to say that a common type of chemical property is flammability. So, basically, how easy is it for something to catch fire? Next, we have, a skull with some bones. We know that this represents death in some way, but here when we use this symbol, it means toxicity. Is this substance toxic? Is it toxic to me? Can it slowly be hurting me? Next, we have an image of liquid coming from little vials, and when they drip, they break down whatever they're touching. That's because they're corrosive. So we'd say here that this is an image for corrosion. Next, we have a beaker, and we have bubbles emanating from it. Remember, chemical reactions sometimes cause a change that we can visually see. That could be a color change or in this case, the formation of bubbles. This is telling us that a reaction is occurring and so it represents reactivity. So reactivity represents a chemical property. Next, we have a radioactive symbol, so this represents radioactivity. Now, finally, we have here this purple substance being dumped into a solvent, a liquid. This is representative of solubility. Now solubility has to do with how our solid compound, when it gets thrown into liquid, how the liquid interact with one another. If the compound is soluble, it'll be broken down by the liquid. If the substance is not soluble, then it will not be thoroughly broken down by the liquid. We'll go in greater detail in the idea of solubility in chapters later on, but for now, just realize that solubility represents a chemical property. So just remember, connected to chemical properties is the idea of chemical reactions. Remember, when we're talking about chemical reactions, we're talking about chemical changes. Use this to guide you to the correct question, correct answer in a question whenever dealing with chemical properties. Now that we've seen this, let's click on the next video and take a look at an example question.

Chemical Properties Example 1

So here, let's take a look at this example question. It says, "Which of the following is not a chemical property of an unknown element?" Now remember, a chemical property is associated with matter undergoing some type of chemical reaction, where the composition, the chemical bonds, and therefore, the identity of our original substance is forever changed. If we take a look here at option A, it says it has a yellow-orange color. Now this is just talking about the appearance of the element, the way it looks. And we haven't talked about it yet, but this represents a physical property. The way something looks is associated with its physical property. Now, even though we haven't talked about physical properties yet, we know that this could not be a chemical property because it's not talking about how that yellow-orange substance is reacting or involved in a chemical reaction. So this would be our answer. This is not a chemical property.

If we look at the other options, it is very soluble in an acid solution. Soluble, meaning we're dealing with solubility, which is one of our key chemical properties we talked about above, so this would be a chemical property. It is radioactive. Radioactivity is also another chemical property we've talked about. It experiences rusting when exposed to pure oxygen gas. So we've been talking about this consistently, that the rusting of metals is an example of an irreversible process. It's an example of a chemical change. It has to do with oxygen from the air chemically binding to the metal, so this represents a chemical reaction and therefore a chemical property. It has high reactivity with acids, so we're talking about its reactivity, which again is another chemical property we talked about. So A would have to be the answer. It's what doesn't represent a chemical property. It's talking about the appearance of the element, not necessarily its reactivity or its involvement in a type of chemical reaction.

Now that we've seen this example, click on the next video, and let's take a look at the practice question.

Which of the following represents a chemical property of hydrogen gas?

• A. It exists as a gas at room temperature.
• B. It is less dense than air.
• C. It reacts explosively with oxygen gas.
• D. It is a colorless gas.
• E. It is a tasteless molecule.

Here’s what students ask on this topic:

What are chemical properties and how are they different from physical properties?

Chemical properties are characteristics of a substance that become evident during a chemical reaction, indicating the ability of a substance to undergo specific chemical changes. Examples include flammability, toxicity, corrosion, reactivity, radioactivity, and solubility. These properties are intrinsic to the substance's chemical identity and composition. In contrast, physical properties can be observed or measured without changing the substance's chemical identity. Examples of physical properties include color, melting point, boiling point, density, and state of matter. While physical changes are usually reversible and do not alter the substance's chemical structure, chemical changes result in the formation of new substances with different properties.

What is flammability and why is it considered a chemical property?

Flammability is the ability of a substance to catch fire and burn in the presence of oxygen. It is considered a chemical property because it involves a chemical reaction between the substance and oxygen, resulting in the formation of new products such as carbon dioxide, water, and other compounds. This reaction alters the chemical composition and identity of the original substance, which is a hallmark of chemical properties. Understanding flammability is crucial for safety and handling of materials, especially in industries where fire hazards are a concern.

How does toxicity relate to chemical properties?

Toxicity is a chemical property that describes the potential of a substance to cause harm to living organisms. It is related to the chemical composition and structure of the substance, which determines how it interacts with biological systems. Toxic substances can interfere with biological processes, leading to adverse health effects or death. The study of toxicity involves understanding the dose-response relationship, exposure routes, and the mechanisms by which the substance exerts its harmful effects. This knowledge is essential for assessing risks and implementing safety measures in various contexts, such as pharmaceuticals, environmental protection, and occupational health.

What is the significance of reactivity in chemical properties?

Reactivity is a chemical property that indicates how readily a substance undergoes chemical reactions with other substances. It is significant because it determines the conditions under which a substance will react and the types of products formed. Highly reactive substances can pose safety hazards, such as explosions or toxic releases, and require careful handling and storage. Reactivity is influenced by factors such as temperature, pressure, concentration, and the presence of catalysts. Understanding reactivity is crucial for predicting and controlling chemical processes in industrial applications, laboratory experiments, and everyday life.

Why is solubility considered a chemical property?

Solubility is considered a chemical property because it describes the ability of a substance (solute) to dissolve in a solvent, forming a homogeneous solution. This process involves interactions at the molecular level, where the solute particles are surrounded and separated by solvent molecules. The extent of solubility depends on the chemical nature of both the solute and the solvent, as well as temperature and pressure. Solubility is important in various fields, such as pharmaceuticals, where it affects drug delivery and bioavailability, and environmental science, where it influences the distribution and fate of pollutants.