Just Chemistry- Introduction

Ms.Allison's Classroom
Lesson 1

In our everyday lives we often carry out our daily activities without even realizing that we are using scientific techniques.If you've ever forgotten a pot of salt water on the stove - and observed that the water dries out to leave the a white substance (salt) or used a magnet to pick up pins just for the fun of it, you really are observing Separating Techniques. A mixture is a physical combination of different substances which are mixed together but are not chemically combined, believe it or not no matter what the mixture contains it can be separated with right techniques.There are more than ten (10) methods by which we can separate mixtures, Fig.1 below shows concept map of a few.      

Fig.1 A Concept Map Showing Some Common Separating Technique 

What are the types of separation techniques?

• Crystallization
• Filtration
• Decantation
• Sublimation
• Evaporation
• Simple distillation
• Fractional distillation
• Chromatography
• Centrifugation
• Separating funnel
• Magnetic separation
• Precipitation

How is a homogeneous mixture different from a heterogeneous mixture?

Most materials in our surroundings are mixtures of two or more components. Mixtures are either homogeneous or heterogeneous. Homogeneous mixtures are uniform in composition, but heterogeneous mixtures are not uniform in composition.

Air is a homogeneous mixture and oil in water is a heterogeneous mixture. Homogeneous and heterogeneous mixtures can be separated into their components by several physical methods. The choice of separation techniques is based on the type of mixture and difference in the chemical properties of the constituents of a mixture.

Copy the link to find out more:
https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/introduction-to-chemistry-1/classification-of-matter-27/substances-and-mixtures-179-3707/