Introduction to Matter
introduction-to-matter
Physical Nature of Matter
physical-nature-of-matter
Particles Have Space Between Them
particles-have-space
Particles Attract Each Other
particles-attract
States of Matter
states-of-matter
Change of State: Effect of Temperature
change-of-state-temperature
Sublimation and Effect of Pressure
sublimation-pressure
Evaporation
evaporation
Summary & Practice Questions
summary-questions
Pure Substances & Mixtures
pure-substances-mixtures
Types of Mixtures
types-of-mixtures
What is a Solution?
what-is-solution
Concentration of Solutions
concentration-of-solutions
Suspensions & Colloids
suspensions-colloids
Separation Techniques - Part 1
separation-techniques-1
Separation Techniques - Part 2
separation-techniques-2
Crystallisation
crystallisation
Physical & Chemical Changes
physical-chemical-changes
Elements & Compounds
elements-compounds
How do we judge whether milk, ghee, butter, salt, spices, mineral water or juice that we buy from the market are pure?
| Perspective | Meaning of "Pure" |
|---|---|
| Common Person | No adulteration |
| Scientist | Single type of particles |
For a scientist, all these consumable things are actually mixtures of different substances and hence not pure!
For example, milk is a mixture of:
A pure substance consists of a single type of particles. All constituent particles have the same chemical nature.
Examples of Pure Substances:
A mixture contains more than one pure substance.
Examples:
Dissolved sodium chloride can be separated from water by evaporation (physical process). However, sodium chloride itself cannot be separated into its chemical constituents by any physical process — it requires a chemical reaction!