Composite, compound and Alloy are usually very confusing terms to some students of chemistry. In this article, get to understand the underlying difference between Alloy, compound and composite. The basis of distinction include: Description, Bonding, appearance, conductivity, physical properties, chemical reaction, separation, examples, boiling and melting points.
Key Differences
Description
- Alloy: An alloy is a mixture of at least two elements with one of those elements being a metal. Alloys can be in both liquid and solid forms.
- Composite: A composite is a mixture of two or more elements, but it does not contain metals in its composition. The components in a composite are always chemically and physically different from one another.
- Compound: A compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds.
Bonds
- Alloy: Sometimes alloys do not have bonds between them.
- Composite: Composite usually has bonds between molecules.
- Compound: Just like composite, compounds usually have bonds between molecules.
Chemical Reaction
- Alloy: Elements of an alloy do not combine through a chemical reaction. The mixing is generally done at very high temperature where the elements and metals are melted, mixed and left to cool.
- Composite: A chemical reaction is involved in mixing the constituent elements of a composite.
- Compound: It is not possible to obtain a compound by just mixing few elements together, but they are only achievable through a specific chemical reaction.
Physical Properties
- Alloy: The alloy has physical properties intermediate between those of the constituent metals; but the chemical properties of each element remain unaffected.
- Composite: The components in a composite are also always chemically and physically different from one another.
- Compound: All compounds have fixed properties i.e have a definite chemical composition, the chemical properties of each element is affected.
Appearance
- Alloy: Alloys have a luster due the presence of metal.
- Composite: Do not have a luster.
- Compound: Compound can have a luster or not.
Separation of Constituent Elements
- Alloy: The constituent elements that make up an alloy can be separated by physical means such as melting.
- Composite: The constituent elements that make up a composite can only be separated through extraction or electrochemical methods.
- Compound: The constituent elements that make up a compound can only be separated through extraction or electrochemical methods.
Melting and Boiling Points
- Alloy: The melting and melting points of an alloy is not always defined, alloys can be boiled or melted at different temperatures.
- Composite: Composite can be boiled and melted a definite temperature.
- Compound: The melting and boiling points of a compound is always defined, they can be boiled or melted at a definite temperature.
Conductivity
- Alloy: Almost all alloys are good conductors of electricity due to presence of a metal.
- Composite: Polymeric composites can conduct electricity whereas others are poor conductors.
- Compound: Compounds with metallic elements are good conductors of electricity whereas compounds whose constituents are nonmetallic elements are poor conductors of electricity.
Composition
- Alloy: Alloys always have at least one metal element.
- Composite: Composites do not have any metal atoms.
- Compound: Compounds are either all metals or all non-metals.
Uniformity
- Alloys: Alloys can either be homogeneous or heterogeneous.
- Composite: Composite is always heterogeneous and will never form a homogeneous mixture.
- Compound: Compound is always homogeneous.
Common Examples
- Alloy: Example of alloys include steel, Bronze, Brass, pewter, cast and wrough iron, duralumin, monel, solder and sterling silver.
- Composite: Examples of composite materials include composite wood such as plywood, fiberglass, ceramic composite and concrete.
- Compounds: Examples of compounds include water, sodium chloride, magnesium oxide, potassium chloride, copper II sulphate, hydrogen chloride etc.
Differences Between Alloy, Composite And Compound In Tabular Form
| Basis of Comparison | Alloy | Composite | Compound |
| Definition | An alloy is a mixture of at least two elements with one of those elements being a metal. Alloys can be in both liquid and solid forms. | A composite is a mixture of two or more elements, but it does not contain metals in its composition. | A compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds. |
| Bonds | Sometimes alloys do not have bonds between them. | Composite usually has bonds between molecules. | Just like composite, compounds usually have bonds between molecules. |
| Chemical Reaction | Elements of an alloy do not combine through a chemical reaction. The mixing is generally done at very high temperature where the elements and metals are melted, mixed and left to cool. | A chemical reaction is involved in mixing the constituent elements of a composite. | It is not possible to obtain a compound by just mixing few elements together, but they are only achievable through a specific chemical reaction. |
| Physical Properties | The alloy has physical properties intermediate between those of the constituent metals; but the chemical properties of each element remain unaffected. | The components in a composite are also always chemically and physically different from one another. | All compounds have fixed properties i.e have a definite chemical composition, the chemical properties of each element is affected. |
| Appearance | Alloys have a luster due the presence of metal. | Do not have a luster. | May have a luster or not. |
| Separation of Constituent Elements | The constituent elements that make up an alloy can be separated by physical means such as melting. | The constituent elements that make up a composite can only be separated through extraction or electrochemical methods. | The constituent elements that make up a compound can only be separated through extraction or electrochemical methods. |
| Melting and Boiling Points | The melting and melting points of an alloy is not always defined, alloys can be boiled or melted at different temperatures. | Composite can be boiled and melted a definite temperature. | The melting and boiling points of a compound is always defined, they can be boiled or melted at a definite temperature. |
| Conductivity | Almost all alloys are good conductors of electricity due to presence of a metal. | Polymeric composites can conduct electricity whereas others are poor conductors. | Compounds with Metallic elements are good conductors of electricity whereas compounds whose constituents are nonmetallic elements are poor conductors of electricity. |
| Composition | Alloys always have at least one metal element. | Composites do not have any metal atoms. | Compounds are either all metals or all non-metals. |
| Uniformity | Alloys can either be homogeneous or heterogeneous. | Composite is always heterogeneous. | Compound is always homogeneous. |
| Examples | Example of alloys includes steel, Bronze, Brass, pewter, cast and wrough iron, duralumin, monel, solder and sterling silver. | Examples of composite materials include composite wood such as plywood, fiberglass, ceramic composite and concrete. | Examples of compounds include water, sodium chloride, magnesium oxide, potassium chloride, copper II sulphate, hydrogen chloride etc. |
What are the similarities between Alloy, Composite and Compound?
- Compound, Alloy and Composite are combined in a definite ratio or in any proportion.
- Alloy, Compound and Composite consist of two or more substances/elements.
- Alloy, Compound and Composite have physical and chemical properties.
- The constituents or components of a Compound, Alloy and Composite can easily be separated.
Summary
What is the main difference between Alloy, Composite and Compound?
- An alloy is a mixture of at least two elements with one of those elements being a metal. Alloys can be in both liquid and solid forms.
- A composite is a mixture of two or more elements, but it does not contain metals in its composition. The components in a composite are always chemically and physically different from one another.
- A compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds.