Difference Between Compound and Mixture

Main Difference – Compound vs Mixture

A compound consists of different kind of atoms which are chemically bonded. A mixture is made up of two or more different kinds of substances (atoms, molecules or compounds) physically intermingled. The main difference between Compound and Mixture is that compounds are chemically bonded whereas mixtures are not.

This article explains,

1. What is a Compound?
          – Definition, Characteristics, Types of Bonding, Examples

2. What is a Mixture?
          – Definition, Characteristics, Examples

3. What is the difference between Compound and Mixture?Difference Between Compound and Mixture - Comparison Summary

What is a Compound – Definition, Characteristics, Types of Bonding, Examples

Compounds are made of elements. A particular compound consists of two or more elements which are chemically bonded. A compound may be entirely different from the elements that they are made up of. For example, Na is a highly reactive metal, and Cl2 is a toxic gas. However, NaCl is a salt which is used for cooking. Another fine example is water which is made up of H2 and O2. Water is a liquid despite both its components being gases.

In certain compounds, the proportions of the content of the atom remain constant and are unique to that particular compound. If the proportion differs, it gives rise to a new compound. This scenario is elaborated by following examples.

Nitrogen and Oxygen give rise to these two compounds.

N2(g) + O2(g)      →     2NO(g)      Nitric Oxide or Nitrogen Oxide

2NO(g) + O2(g)       →     2NO2(g) Nitrous Oxide or Nitrogen  Dioxide

Although Nitrogen Oxide and Nitrous Dioxide are composed of the same elements, their compositions are different. Hence, it gives rise to two different compounds.

Compounds are formed when the attractive forces between the member atoms are greater than that of repulsive forces. Compounds are generally made by either covalent or ionic bonding. Energy is either taken in or given out while making compounds by chemical bonding.

Covalent Bonding 

Electrons are shared by participating atoms as shown below. These kinds of compounds are called covalent compounds. If the two atoms are similarly attracted towards electrons (similar electronegativity), the compound is non-polar. However, if the electronegativity gap between the two atoms is huge, the compound becomes a polar one. A water molecule is the best example of this phenomena.

Non-polar compounds – Methane, Ammonia, Hexane

Polar Compounds  – Water, CF, HFDifference Between Compound and Mixture

Ionic Bonding

Electrons are entirely transferred from one atom to the other. Hence, an electronic charge appears on both the atoms involved in the bonding. Compounds born from these bonds are mainly solids with high melting points and can conduct electrical current. Metal and non- metal elements partner up in forming these type of compounds.

Components of a compound cannot be physically separated. They can be only separated by chemical methods or electrolysis.

What is a Mixture – Definition, Characteristics, Types of Bonding

A mixture is a combination of two or more elements and/or compounds. Though these components are present together, neither are they bonded chemically nor do they make new substances. A good example is sand and water mixture where both components are not chemically bonded and can be separated as individual substances by filtration. Other physical means of separation are evaporation, distillation, chromatography, centrifugation and extraction. For these separation methods, physical properties of components in a mixture are considered. Some of these physical properties are density, size and solubility.

Components in compounds retain their individual characteristics. When you taste a salty water solution, you can feel the salty taste on your tongue. That indicates that the salt is able to give out its characteristic taste even when mixed with water. Mixtures do not have their own properties as compounds do.

Mixtures are often homogeneous or heterogeneous.

Homogeneous mixtures – The composition of the mixture is the same throughout.

                                                   Ex:- Salt dissolved in water

Heterogeneous mixtures – Composition may vary from point to point in the mixture.

                                                   Ex:- Smog

The air we breathe, and the vast blue ocean can be considered as the largest mixtures found on earth. Both are heterogeneous mixtures.

Key Difference - Compound vs Mixture

Difference Between Compound and Mixture

Bond

Compounds: Components are chemically bonded.

Ex:- NaCl, H2O

Mixtures: Components are not chemically bonded. 

Ex:- Salty Water, Sand and Sugar

Separation 

Compounds: Components cannot be physically separated. They can be separated through electrolysis.

Mixtures: Components can be physically separated easily through methods such as filtration, chromatography, centrifugation, dialysis, evaporation, and distillation. 

Characteristics

Compounds: Compounds show their own characteristics, not the individual features of components.

Mixtures: Compounds do not show their own characteristics. Individual features of components are displayed.

Ratio

Compounds: Ratio of components is fixed.

Mixtures: Ratio of components may vary. 

Boiling Point and Melting Point

Compounds: Boiling point and melting point are constant for a particular compound.

Mixtures: Boiling point and melting point are not constant.

Energy Transfer

Compounds: Energy is given out or in to prepare compounds through chemical bonding. 

Mixtures: There is no or little energy transfer.

Categories

Compounds: Compounds can be covalent or ionic.

Mixtures: Mixtures can be homogeneous or heterogeneous.

Reference List:

“Our Objective.” Distinguish Between Mixture and Compound (Theory) : Class 9 : Chemistry : Amrita Online Lab. N.p., n.d. Web. 31 Jan. 2017.
Ophardt, Charles. ” Introduction to Ionic Compounds.” Virtual Chembook. Elmhurt College, 2003. Web. 31 Jan. 2017.
 

Image Courtesy:

“Covalent” By DynaBlast – Created with Inkscape (CC BY-SA 2.5) via Commons Wikimedia 

 “SaltInWaterSolutionLiquid” By Chris 73 / Wikimedia Commons (CC BY-SA 3.0) via Commons Wikimedia

About the Author: Pabasara

Pabasara posses a Bachelor's Degree in Chemistry and is reading for M.Phil. in Chemistry. She has working experience in both academic and industry environments.

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