Match the items in Column I with relevant items in Column II.

Column I

Column II

A.

Ions having a positive charge

1.

+7

B.

The sum of oxidation number of all atoms in a neutral molecule

2.

–1

C.

Oxidation number of hydrogen ion. (H+)

3.

+1

D.

Oxidation number of fluorine in NaF

4.

0

E.

Ions having a negative charge

5.

Cation

6.

Anion

Codes:

Options:  A   B   C   D   E 
1. 5 4 3 2  6
2. 1 2 3 5  4
3. 5 4 3 2 1
4. 4 5 3 2 1
Subtopic:  Introduction to Redox and Oxidation Number |
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The oxidation number of iodine in \(IO^-_3, IO^-_4, KI \) and \(I_2\) respectively are:

1. -2, -5, -1, 0
2. +5, +7, -1, 0 
3. +2, +5, +1, 0
4. -1, +1, 0, +1
Subtopic:  Introduction to Redox and Oxidation Number |
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Match the compounds of iron given in column I with their respective oxidation states given in column II, and mark the appropriate choice.
Column I
(Compound)
Column II
(Oxidation states of Fe)
(A) \(K_3[Fe(OH)_6]\) (i) +8/3
(B) \(K_2[FeO_4]\) (ii) +2
(C) \(FeSO_4(NH_4)_2SO_4.6H_2O\) (iii) +3
(D) \(Fe_3O_4\) (iv) +6

1. (A) →(iii), (B)→(i), (C) →(ii), (D)→ (iv)
2. (A) →(iii), (B)→(iv), (C) →(ii), (D)→ (i)
3. (A) →(i), (B)→(iii), (C) →(ii), (D)→ (iv)
4. (A) →(iv), (B)→(ii), (C) →(i), (D)→ (iii)
Subtopic:  Introduction to Redox and Oxidation Number |
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Match the items in column I with column II.
(O.S = oxidation state)
 
Column I Column II
a. Fe O.S in Fe2O3 i. +2
b. Mn O.S in MnO2 ii. +3
c. Mn O.S in MnO iii. +4

1. a=i; b=ii; c=iii
2. a=ii; b=iii; c=i
3. a=iii; b=ii; c=i
4. a=ii; b=i; c=iii
Subtopic:  Introduction to Redox and Oxidation Number |
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The average oxidation number of sulphur in \(\mathrm{Na}_2 \mathrm{~S}_4 \mathrm{O}_6\) is:

1. 1.5 
2. 2.5 
3. 3.0 
4. 2.0 
Subtopic:  Introduction to Redox and Oxidation Number |
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S8(s) + 12NaOH(aq) → 4Na2S(aq) + 2Na2S2O3(aq) + 6H2O(l)
A                                        B                     C

The oxidation state of sulfur in the given equation is A, B, and C.

A, B, and C are respectively:
1. 0, -2, +2
2. -2, 0, -2
3. 0, +2, -2
4. -2, -2, +2
Subtopic:  Introduction to Redox and Oxidation Number |
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Among the following compounds, which one is a transition metal with an oxidation number of zero?

1. \(\mathrm{\left[{Fe}\left({H}_2 {O}\right)_3\right]({OH})_2}\)

2. \(\mathrm{\left[{Co}\left({NH}_3\right)_6\right] {Cl}_2}\)

3. \(\mathrm{\left[{Ni}({CO})_4\right]}\)

4. \(\mathrm{\left[{Pt}\left({C}_2 {H}_4\right) {Cl}_3\right]}\)

Subtopic:  Introduction to Redox and Oxidation Number |
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Which of the following is not a valid rule for determining oxidation numbers?
1. For ions, the oxidation number is equal to the charge of the ion.
2. Oxygen always has an oxidation number of -2 in all its compounds.
3. Fluorine has an oxidation number of -1 in all its compounds. 
4. Hydrogen usually has an oxidation number of +1, except in binary hydrides of alkali and alkaline earth metals, where it is -1.
Subtopic:  Introduction to Redox and Oxidation Number |
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What is the oxidation number of sulphur in \(S_8\) molecule?
1. Three (6) 2. Zero (0)
3. Two (2) 4. Three (3)
Subtopic:  Introduction to Redox and Oxidation Number |
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Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): HNO3 acts as an oxidizing agent.
Reason (R):

The oxidation state of nitrogen in HNO₃ is +5, which cannot increase further. Thus, the oxidation state of nitrogen in HNO₃ can only decrease.

In light of the above statements, choose the correct answer from the options given below:
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. Both (A) and (R) are False.
Subtopic:  Introduction to Redox and Oxidation Number | Oxidizing & Reducing Agents |
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