Question

1) Name the reducing agent in the following reaction
3MnO2 + 4AI= 3Mn + 2Al2O3

State which is more reactive, Mn or Al and why.

2) Name the type of chemical reaction in the following equation
a. CaO + H2O = Ca(OH)2
b. 3 BaCl2 + Al(SO4)3= 3BaSO4 + AICI3
c. 2FeSO4 = Fe2O3 + SO2+ SO3
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Answer 1

Answer:

1. Aluminum (Al) is the reducing agent.

2. Al is more reactive than Mn.

3. Oxidation Reaction.

Explanation:

Al is ‘more reactive’ than Mn as it replaces the Mn from its compound .

Here  changes to Mn. The ‘oxidation number’ of Mn in  is +4 whereas the oxidation number of Mn is zero. Hence the change in oxidation number occurs from +4 to 0. Overall oxidation number decreases hence it is reduction and  is called as oxidizing agent.

On the contrary, the oxidation number of Al is zero and it changes to +3 in. Hence the ‘oxidation number increases’ so it is an oxidation reaction and Al is a reducing agent.

Answer 2

1)Reducing agent is the element which reduces other element to oxidise itself. So here aluminium (Al) is the reducing agent.

Aluminium is more reactive than Manganese as aluminium displaces MnO2.

2)a) Combination reaction.

b) Double displacement reaction.

c) Decomposition reaction.