Question

1.Why does the colour of copper sulphate solution change when
an iron nail is dipped in it?
2.Give an example of a double displacement reaction other than
the one given in Activity 1.10.
3.Identify the substances that are oxidised and the substances
that are reduced in the following reactions.
(i) 4Na(s) + O2(g) → 2Na, O(s)
(ii) CuO(s) + H, (g) → Cu(s) + H,O(1)





please solve this problems​

Answer 1

Answer:

1.Why does the colour of copper sulphate solution change when an iron nail is dipped in it?

When an iron nail immersed in the solution of copper sulphate than iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green.

2.Give an example of a double displacement reaction other than the one given in Activity 1.10.

Chemical Reactions and Equations

Give an example of a double displacement reaction other than the one given in Activity 1.10. ... Its chemical formula is CaO. (ii) Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime).

3.Identify the substances that are oxidised and the substances that are reduced in the following reactions.

(i)The substance oxidised is sodium and the substance reduced is oxygen gas. (ii) The substance oxidised is Hydrogen gas and the substance reduced is copper oxide.

Answer 2

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1. Why does the colour of copper sulphate solution change when an iron nail is dipped in it..?

Ans: When an iron nail dipped in the copper sulphate solution than iron displaces copper from the copper sulphate because iron is more reactive than copper. Therefore the colour of the copper sulphate solution changes.

The reaction involved here is:

Fe (s) + CuSO4 (aq) → FeSO4 (aq) + Cu (s)

2. Give an example of a double displacement reaction other than the one given in Activity 1.10.

Ans: 2KBr (aq) + BaI2 (aq) → 2KI (aq) + BaBr2 (aq)

3. Identify the substances that are oxidised and the substances that are reduced in the following reactions.

(a) 4Na (s) + O2 (g) → 2Na2O (s)

(b) CuO (s) + H2 (g) → Cu (s) + H2O (l)

Ans: (a) Sodium (Na) is oxidised as it gains oxygen and oxygen gets reduced.

(b) Copper oxide (CuO) is reduced to copper (Cu) while hydrogen (H2) gets oxidised to water (H2O).