3. Give one example each of a chemical reaction showing the following characteristics
1 a, evolution of a gas
b. change of colour
e. formation of precipitate
d, change of state from liquid to gas
e. change of state from gas to liquid
dothermic reactions and exothermic reactions .
Answers
Answer:
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 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 gas.
Explanation:
your 3d answer how can it's possible...