Solution

Cu + H₂SO₄ ⟶ CuSO₄ + H₂ (as acid)
H₂ + H₂SO₄ ⟶ 2H₂O + SO₂ (as oxidant)
In (a), H₂SO₄ acts just as dehydrating agent.
In (b), it acts just as an oxidant.
In (d), it neither acts as oxidant nor as acid.

In oxygen difluoride, the oxidation number of oxygen is :

– 2
– 1
+ 2
+1, – 2

Solution

Let oxidation state of oxygen in OF₂= x
∴ x+ ( – 1 × 2) = 0
∴ x= + 2

In haemoglobin the iron is in the following oxidation state :

Solution

In haemoglobin, Fe is in +2 oxidation state.

One mole of N₂H₄ loses 10 moles of electrons to form a new compound, y. Assuming that all nitrogen appear in the new compound, what is the oxidation state of nitrogen in y (There is no change in the oxidation state of hydrogen )

–1
–3
+3
+5

Solution

The oxidation states of the most electronegative element in the products of the reaction, BaO₂ with dil. H₂SO₄ is

0 and –1
–1 and –2
–2 and 0
–2 and –1

Solution

BaO₂ + H₂SO₄ ⟶ BaSO₄ + H₂O₂
Oxygen is the most electronegative element in the reaction and has the oxidation states of–1 (in H₂O₂)and –2 (in BaSO₄). In H₂O₂, peroxo ion is present.

Solution

Which of the following statements is not correct?

CaOCl₂ is a mixed salt of two acids HCl and HOCl.
Oxidation number of chlorine in CaOCl₂ is zero since it exists as Cl₂
Oxidation number of chlorine is – 1 since it exists as Cl^-
Oxidation number of chlorine is + 1 since it exists as ClO^-

Which of the following involves a redox reaction?

Reaction of H₂SO₄ with NaOH
Production of ozone from oxygen in the atmosphere by lightening
Production of nitrogen oxides from nitrogen and oxygen in the atmosphere by lightening
Evaporation of water

Solution

In which of the following reaction, oxidation number of N remains unchanged ?

2NO₂ + H₂O ⟶ HNO₃ + HNO₂
N₂ + O₂ ⟶ 2NO
2NO₂ ⟶ N₂O₄
NH₄NO₂ ⟶ N₂ + 2H₂O

Solution

The oxidation number of N in NO₂ is +4 and in N₂O₄ is also + 4(i.e. no change)

The oxide, which cannot act as a reducing agent, is

NO₂
SO₂
CO₂
ClO₂

Solution

Carbon has the maximum oxidation state of + 4,therefore carbon dioxide (CO₂) cannot act as a reducing agent.

UnAttempted

0

Attempted

0

Correct

0

Wrong

0

Complete