LEARN MORE ON PHYSICAL AND CHEMICAL CHANGE
All explanations are put in the simplest and easiest ways possible for fast comprehension. Enjoy.
Physical changes:These are the changes which can be easily reversed and no new substances are formed after the process. Examples are:
1) The solution of table salt in water
2) A change in the state of matter
3) Melting of ice
4) Liquefaction of gases
5) Shredded paper etc.
Separation of mixture: evaporation distillation fractional distillation sublimation etc.
The separation process includes all physical processes such as freezing condensation vaporization etc.
READ MORE: the different types of separation techniques
Learn all about mixtures
Chemical changeChemical changes are changes which cannot be easily reversed to its original state and new substances are formed.
1) Burning of candle
2) The solution of metals and limestone in acids
3) Slacking of lime
4) Electrochemical process
5) Cracking of petroleum
6) Fermentation and decay of substances etc.
READ MORE: all about compounds
Differences between physical and chemical changesPhysical change chemical change
a) it can be easily reversed it cannot be easily reversed
b) no new substances are formed a new substance is formed
c) it liberates little or no energy it liberates a lot of heat energy
d) it cannot be represented it can be represented by a by any chemical equation.
Experiment shows that zinc oxide a physical changeAim: To show that zinc oxide undergoes a physical change.
Method: Heat zinc oxide in a boiling tube then remove tube from the flame and cool it.
Observation: While zinc oxide turns yellow on heating it regains its original colour on cooling (white colour).
Conclusion: The change in colour is a physical change because it is easily reversible without affecting the chemical nature of it.
Experiment two: chemical changes
Aim: To show that chemical changes takes place a)When a metallic zinc is added to dilute hydrogen sulphate H2SO4. b) When copper(ii) trioxocarbonate (iv) (CUCO3)
Method: a) Add a plate of metallic zinc to some dilute hydrogen sulphate H2SO4 in a boiling tube when the reaction is completed the solution is evaporated to dryness.
b) Add some amounts of copper (ii) trioxocarbonate (iv) (CUCO3) in a boiling tube and hold it firmly with a holder in a flame record your observations after a few minutes.
a) Gas bubbles (hydrogen) are released as zinc gradually dissolves in the acid on complete evaporation a white recipe of ZnSO4 is left behind.
b) Gas bubbles (carbon (iv) oxide CO2) are released on cooling a black recipe of copper (ii) oxides left behind.
Conclusion New substances are formed when zinc is added to dilute hydrogen sulphate (H2SO4) and copper (ii) trioxocarbonate (iv) (CUCO3) is heating.
We witness several physical and chemical changes in our everyday lives and most industries around us from the rubber plastic brewery polymer industries to mere freezing your bottled water in a refrigerator. Reactions such as: Fermentation process which can be represented by several chemical equations and cannot by reversed is called a chemical change. 2C6H6O6 --- 2C2H5OH + 2CO2 Physical changes on the other hand is used to separate mixture into their component compound while for a chemical change an entirely new product is formed. If you liked this article kindly share this if you have any additions or suggestions comment below. Science