What information is conveyed by a balanced chemical equation?
The basic knowledge that is conveyed by a balanced chemical equation are as follows:
1. The respective formulas of the reactants and products.
2. The respective masses of the reactants and products.
3. The total number of molecules involved in the process.
Give 2 examples of each of the following changes occurring during a chemical reaction :
1) Change of state of the reactants
2) Change of colour
3) Evolution of gas
4) Formation of precipitate
Answer:
Characteristics of chemical reaction:
1) Change of state of the reactants:
Example:
Ammonia gas reacts with hydrogen chloride gas to produce solid ammonium chloride.
2)Change of colour
Example:
Wehne few pices of Fe are added to the blue copper sulphate solution, the colour of the solution fades
and turns into light green due to the formation of ferrous sulphate.
3)Evolution of gas
Example:
4) Formation of precipitate
Example:
When silver nitrate is added to sodium chloride, white insoluble precipitate of silver chloride is formed.
When ferrous sulphate solution is added to the sodium hydroxide, a dirty green precipitate ferrous hydroxide is formed.





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