03-25, 18:30
chemical reactions and equations
Physical changes
The taste and odour of food material containing fat and oil change when they are left expossed to
air for long time .
It cause due to oxidation of fat and oil present in food material.
Chemical changes
Those changes in which new substance are formed are called chmeical changes . In q chemical
changes , the substance involved changed their identity. They get converted into entire new
substance. The new substance usually cannot be returned to their original form.
, Chemical reaction and equation
Chemical reaction are the process in which new substance with new properties are formed. The new
substance formed have entirely different properties form their constituents.
Chemical reaction involve chemical change.
During a chemical reaction, atoms of one element do not change into those of another elements.
Only a rearrement of atom takes place in a chemical reaction.
H2 +O2 = H2O
A + B = AB
Chemical equation
Method of representing or chemical reactions in the form of symbols and formula of the substance
involved is called chemical equation.
Reactant and product
H2 +O2 = H2O
[Reactant ] [Product]
Case study of magnesium ribbon
, When a magnesium ribbon is heated , it burns in air with a dazzling white flame to form a white
powder called magnesium oxide. Actually, on heating, magnesium ribbon combines with oxygen
present in air to form magnesium oxide :
Mg + O2 = MgO
Why should a magnesium ribbon be cleaned before in air ??
Because magnesium reacts with the oxygen present in air ro form a layer of magnesium oxide on its
surface, which interferes with burning process.
How do we know that a chemical reaction has taken palce ??
Evolution of gas
Formation of preciptate
Change in colour
Change in temperature
Change in state
Evolution of gas
Zn +H2So4 = ZnSo4 +H2
chemical reactions and equations
Physical changes
The taste and odour of food material containing fat and oil change when they are left expossed to
air for long time .
It cause due to oxidation of fat and oil present in food material.
Chemical changes
Those changes in which new substance are formed are called chmeical changes . In q chemical
changes , the substance involved changed their identity. They get converted into entire new
substance. The new substance usually cannot be returned to their original form.
, Chemical reaction and equation
Chemical reaction are the process in which new substance with new properties are formed. The new
substance formed have entirely different properties form their constituents.
Chemical reaction involve chemical change.
During a chemical reaction, atoms of one element do not change into those of another elements.
Only a rearrement of atom takes place in a chemical reaction.
H2 +O2 = H2O
A + B = AB
Chemical equation
Method of representing or chemical reactions in the form of symbols and formula of the substance
involved is called chemical equation.
Reactant and product
H2 +O2 = H2O
[Reactant ] [Product]
Case study of magnesium ribbon
, When a magnesium ribbon is heated , it burns in air with a dazzling white flame to form a white
powder called magnesium oxide. Actually, on heating, magnesium ribbon combines with oxygen
present in air to form magnesium oxide :
Mg + O2 = MgO
Why should a magnesium ribbon be cleaned before in air ??
Because magnesium reacts with the oxygen present in air ro form a layer of magnesium oxide on its
surface, which interferes with burning process.
How do we know that a chemical reaction has taken palce ??
Evolution of gas
Formation of preciptate
Change in colour
Change in temperature
Change in state
Evolution of gas
Zn +H2So4 = ZnSo4 +H2
