Table of Differences Between Compound and Mixture with Examples
Difference Between Compound and Mixture is a foundational concept in JEE Main Chemistry that students must master for clarity in physical and chemical classification of matter. In chemistry, a compound is a pure substance made by chemically combining two or more elements in fixed proportions, giving rise to new properties different from those of its components. By contrast, a mixture is formed when two or more substances are physically blended without any fixed ratio and without any change to their original chemical identities. Understanding these differences is critical for solving classification-based questions, MCQs, and application tasks where you must identify the nature of a given sample or separate it using appropriate techniques.
Compound and Mixture: Definitions and Core Concepts
A compound is defined as a substance formed when two or more different elements combine in a definite, fixed ratio via a chemical reaction. Compounds always exhibit a uniform composition and properties. Water (H2O) is a classic example—hydrogen and oxygen react chemically in a 2:1 ratio to form water, which has completely different properties from both hydrogen and oxygen gases.
A mixture is a physical combination of two or more substances (elements or compounds) that retain their individual properties. The proportions of substances in a mixture can vary. For instance, air is a mixture of nitrogen, oxygen, CO2, water vapour, and more; each component keeps its original properties, and the ratio is not fixed.
Difference Between Compound and Mixture: JEE-Focused Table
| Property | Compound | Mixture |
|---|---|---|
| Formation | By chemical reaction (bond formation) | By physical mixing (no new bonds) |
| Composition | Fixed ratio by mass or atoms | Variable ratio, any proportion |
| Properties | Unique and new; differ from constituents | Retain original properties of each component |
| Separation | Needs chemical methods only | Physical methods suffice (e.g., filtration, distillation) |
| Energy Change | Usually involved (exothermic/endothermic) | No significant energy change |
| Formula | Has a definite chemical formula | No universal formula |
| Purity | Pure substance | Impure; can have variable purity |
| Melting/Boiling Point | Sharp and fixed | Varies with composition; not sharp |
| Examples | Water, sodium chloride, carbon dioxide | Air, saltwater, alloys, soil |
| Types | Only one (homogeneous) | Homogeneous and heterogeneous |
This table is a quick reference for JEE Main; make sure to review all points before your exam.
Examples and Real-Life Applications
Recognising and applying the difference between compound and mixture helps you tackle both theoretical and practical problems in chemistry. Here are several key examples to help you remember:
- Compounds: Water (H2O, essential for life), Sodium chloride (NaCl, common salt), Carbon dioxide (CO2), Methane (CH4), Calcium carbonate (CaCO3)
- Mixtures: Air (breathable mixture), Saltwater (in oceans), Brass (alloy of Cu and Zn), Sand with salt, Petrol with additives
Everyday applications include using magnets to separate iron from sand (mixture), or decomposing water via electrolysis (chemical separation, proof it's a compound). For more on mixtures, visit Mixture – Types and Separation Techniques , and to go deeper into compounds, see Properties of Compounds.
How to Identify: Compound vs Mixture (JEE Tricks)
- If the composition is always fixed and there's a chemical formula, it's a compound.
- If you can separate the components by physical means—like filtration, magnet, evaporation—it must be a mixture.
- Changes in properties (colour, boiling point, reactivity) from constituents suggest a compound; no new properties = mixture.
- Ask: Did you need a chemical reaction to create or break it? Yes = compound; No = mixture.
- Is the system always uniform in nature? All compounds and homogeneous mixtures look uniform, but test with separation methods for confirmation.
For more strategies on classification, review Matter – Classification for broader context, or practice with Some Basic Concepts in Chemistry Practice Paper.
Common Application Traps and Student Mistakes
- Confusing a solution (e.g., sugar in water) as a compound; it's actually a physical mixture.
- Assuming all homogeneous samples are compounds. Alloys like brass are homogeneous mixtures—even though they look uniform.
- Believing air is a compound due to its name; actually, it's a mixture with variable composition.
- Forgetting that many separation techniques (distillation, chromatography) work only for mixtures, not compounds.
- Mixing up physical and chemical changes during formation—remember, only chemical change yields a compound.
Avoiding these mistakes helps you gain accuracy in MCQs and reasoning-based questions. For related distinctions, see Difference Between Element And Compound or Physical and Chemical Changes.
Exam-Oriented Practice Problems: Compound vs Mixture
- Which of the following is a compound: (a) Milk (b) Water (c) Alloys (d) Soil?
- Statement 1: Compounds need a fixed mass ratio. Statement 2: Mixtures have fixed properties. Select the correct option.
- Air can be separated using physical methods. Is it a compound or mixture?
- Choose the odd one out: Brass, Carbon dioxide, Bronze, Soil.
- Identify the mixture(s) from the list: (i) Sodium chloride, (ii) Salad, (iii) Carbon dioxide, (iv) Steel.
More practice is available at JEE Chemistry Question-Answers and JEE Compound vs Mixture Questions.
Summary Table: Compound vs Mixture—At a Glance
| Compound | Mixture |
|---|---|
| Fixed composition; formed by chemical combination | Variable composition; formed by physical blending |
| Unique properties; can only be split chemically | Retains constituents’ properties; separated physically |
To go beyond basic examples and test your skills on chemicals used in mixtures, or see how chemical bonding leads to compounds, refer to Chemical Bonding and Molecular Structure.
Mastering the difference between compound and mixture helps you avoid conceptual traps in JEE Main, improves classification accuracy, and lays a foundation for further studies in topics such as Types of Pure Substances and Difference Between Pure Substance and Mixture. For more expert explanations, trust Vedantu’s Chemistry educators to keep you exam-ready and concept-strong.
FAQs on Compound vs Mixture: Definitions, Differences, and Examples
1. What is the main difference between a compound and a mixture?
The primary difference between a compound and a mixture is how their components are combined and their resulting properties.
- Compounds are pure substances formed by chemically combining elements in a fixed ratio, giving them unique properties distinct from their elements.
- Mixtures consist of two or more substances physically combined in any proportion, with each component retaining its original properties.
- Separation of compounds requires chemical methods, while mixtures can be separated by physical means.
This distinction is key in chemistry classes and in identifying substances in lab experiments and exams.
2. What are 5 differences between compounds and mixtures?
Compounds and mixtures differ in several important ways:
1. Composition: Compounds have elements in a fixed ratio; mixtures can have components in any proportion.
2. Formation: Compounds form by chemical reactions; mixtures form by physical mixing.
3. Properties: Compounds have new properties, different from their constituents; mixtures show the properties of individual components.
4. Separation: Compounds require chemical methods to separate; mixtures can be separated physically.
5. Energy Change: Energy is usually involved in compound formation (chemical change); mixture formation does not involve chemical energy change.
These differences help in distinguishing questions for Class 9-12, JEE, and competitive exams.
3. What are 5 examples of compounds and mixtures?
Compounds and mixtures are found everywhere in daily life and labs.
Examples of Compounds:
- Water (H₂O)
- Carbon dioxide (CO₂)
- Sodium chloride (NaCl)
- Methane (CH₄)
- Ammonia (NH₃)
Examples of Mixtures:
- Air
- Saltwater
- Soil
- Brass (alloy of copper and zinc)
- Sand and iron filings
Knowing these aids quick revision and identification during exams.
4. How can you tell if something is a compound or mixture?
To identify if a substance is a compound or mixture, check these characteristics:
- Fixed ratio: Compounds have a definite formula; mixtures do not.
- Uniformity: Compounds are homogeneous; mixtures can be homogeneous or heterogeneous.
- Separation method: Compounds need chemical methods; mixtures can be separated by physical means.
- Properties: Compounds have unique properties; mixtures retain properties of components.
- Energy change: Compound formation involves chemical change (often with energy change); mixtures do not.
These tips help with MCQ strategies in JEE/NEET and board exams.
5. What are the properties that distinguish a compound from a mixture?
Compounds and mixtures differ mainly in:
- Chemical combination (compounds) vs. physical combination (mixtures)
- Fixed proportion (compounds) vs. variable proportion (mixtures)
- Unique set of properties (compounds) vs. individual component properties (mixtures)
- Separation by chemical means (compounds) vs. physical means (mixtures)
- Homogeneity (compounds) vs. homogeneous or heterogeneous (mixtures)
Understanding these properties helps in practical and theoretical chemistry questions.
6. How can you separate a mixture but not a compound?
Mixtures can be separated by physical methods, while compounds need chemical processes for separation.
- Sieving, filtration, evaporation, magnetic separation, and distillation are common physical methods for mixtures.
- Compounds can only be broken down into elements by chemical reactions (e.g., electrolysis of water).
This exam concept is vital in chemistry practicals and competitive syllabi.
7. Why is hydrogen peroxide (H₂O₂) a compound and not a mixture?
Hydrogen peroxide (H₂O₂) is a compound because it consists of hydrogen and oxygen chemically combined in a fixed ratio.
- Its chemical formula (H₂O₂) shows definite proportions.
- It has unique properties different from elemental hydrogen or oxygen.
- It cannot be physically separated into hydrogen and oxygen.
- Only chemical change can break it down.
This example is commonly used in board and JEE/NEET questions.
8. Is air a compound or a mixture? Why?
Air is a mixture, not a compound.
- It contains various gases (like nitrogen, oxygen, carbon dioxide, etc.) physically combined in varying proportions.
- The components of air retain their properties.
- Air can be separated into its components by physical means like fractional distillation.
This is a classic example seen in chemistry exams and textbooks.
9. What is the difference between compound and mixture in chemistry with examples?
In chemistry, compounds are pure substances formed by chemically combining elements, while mixtures are physical combinations of substances.
- Compound Example: Water (H₂O)—hydrogen and oxygen chemically joined.
- Mixture Example: Saltwater—salt and water physically mixed.
Compounds have fixed ratios and unique properties; mixtures have variable ratios and retain their components' properties.
10. Can all mixtures be separated by physical methods?
Most mixtures can be separated by physical methods, but some complex mixtures may require special techniques.
- Simple mixtures (like sand and iron fillings) can be separated using magnets or filtration.
- Homogeneous mixtures (like solutions) may need methods like distillation or evaporation.
- Some mixtures (like alloys) are harder to separate and may need both physical and chemical methods.
This point is important for practical questions in chemistry exams.
