write the chemical equations of thr reaction in which the following changes have taken place with example of each change in colour and change in Temperature and change in state
Answers
Answer:
1.Evolution of gas:
The chemical reaction between zinc and dilute sulphuric acid is characterized by the evolution of hydrogen gas.
Zn(s)+H
2
SO4(aq)→ZnSO
4
(aq)+H
2
(g)
2.Change in colour:
The reaction between the lead nitrate solution and potassium iodide solution.
Pb(NO
3
)
2
(aq)+2KI→PbI
2
(s)+2KNO
3
(aq)
In this reaction colour changes from colourless to yellow.
3.Formation of precipitate:
The action of Barium Chloride on sodium sulphate.
BaCl
2
(aq)+Na
2
SO
4
(aq)→BaSO
4
(s)+2KNaCl(aq)
4.Change in temperature:
The action of dilute sulphuric acid on zinc:
Zn(s)+H
2
SO
4
(aq)→ZnSO
4
(s)+H
2
(g)
In this reaction, heat is evolved.
5.Change in the state:
When the wax is burnt in the form of the wax candle then water and carbon dioxide are formed. Wax is solid, water is a liquid whereas carbon dioxide is a gas.
Explanation:
1.Evolution of gas:
The chemical reaction between zinc and dilute sulphuric acid is characterized by the evolution of hydrogen gas.
Zn(s)+H
2
SO4(aq)→ZnSO
4
(aq)+H
2
(g)
2.Change in colour:
The reaction between the lead nitrate solution and potassium iodide solution.
Pb(NO
3
)
2
(aq)+2KI→PbI
2
(s)+2KNO
3
(aq)
In this reaction colour changes from colourless to yellow.
3.Formation of precipitate:
The action of Barium Chloride on sodium sulphate.
BaCl
2
(aq)+Na
2
SO
4
(aq)→BaSO
4
(s)+2KNaCl(aq)
4.Change in temperature:
The action of dilute sulphuric acid on zinc:
Zn(s)+H
2
SO
4
(aq)→ZnSO
4
(s)+H
2
(g)
In this reaction, heat is evolved.
5.Change in the state:
When the wax is burnt in the form of the wax candle then water and carbon dioxide are formed. Wax is solid, water is a liquid whereas carbon dioxide is a gas.