Question

1. What changes do you observe in the iron nails and colour of copper sulphate solution, if iron nails are dipped in CuSO4 solution for 15 minutes ?
2. Identify the chemical change : Melting of ice or conversion of milk into curd.
3. Why is respiration considered an exothermic reaction ?
4. Why do copper vessel lose shine when exposed to air ?
5. Potato chips manufacturers fill the packet of chips with nitrogen gas. Why ?
6. Why we store silver chloride in dark coloured bottles ?
7. Write a chemical equation of double displacement reaction.
8. N2 + 3H2 → 2NH3 , name the type of reaction.
9. What happens when milk is left open at room temperature during summers ?
10. What happens when quick lime is added to water ?

Answer 1

Answer:

Explanation:

1]Rusting

2] Lactation

3] Because it release Heat

4] Oxidation

5] Prevention of oxidation

Answer 2

Answer:

Explanation:

!] reduction

2] oxidation

3] substitution

4] Sleeping pills

5] Harddrive