Amount of oxalic acid present in a solution can be determined by its titration with KMnO 4 solution in the presence of H 2 SO 4 . The titration gives unsatisfactory result when carried out in the presence of HCl, because HCl:

oxidises oxalic acid to carbon dioxide and water

gets oxidised by oxalic acid to chlorine

furnishes H + ions in addition to those from oxalic acid

Reaction between acidified K 2 Cr 2 O 7 and iron (II) ions shown by the equation: Cr 2 O 7 2 - (aq) + 6Fe 2+ (aq) +14H + (aq) → 2Cr 3+ (aq) + 7H 2 O(l) + 6Fe 3+ (aq) The correct statement among the following is -

Colour of the solution changes from green to blue

The decomposition of KClO 3 to KCl and O 2 on heating is an example of:

disproportionation or auto redox change

Chemistry - Redox Reactions - Quiz-2

The oxidation state of Ni in Ni(CO)₄ is:

0%

zero
0%

+4
0%

+8
0%

+2

Milliequivalents of a solute in a solution can be given by:

0%

Mzeq_. = M x V_{in mL}
0%

Meq. = N x V_{in mL}
0%

Mzeq. = $\frac{m a s s}{E q . m a s s} \times$ 1000
0%

both 2 and 3

HBr and HI reduce H₂SO₄, HCl can reduce KMnO₄ and HF can reduce:

0%

H₂SO₄
0%

K₂Cr₂O₇
0%

KMnO₄
0%

none of these

Sulphurous acid can be used as:

0%

Oxidising agent
0%

Reducing agent
0%

Bleaching agent
0%

All of the above

When SO₂ is passed through acidified solution of potassium dichromate, then chromium sulphate is formed. The change in oxidation number of chromium is:

0%

+4 to+2
0%

+5 to+3
0%

+6 to+3
0%

+7 to+2

The reaction involving the transfer of five electrons is -

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Mn $O_{4}^{-}$ $\to$ Mn²⁺
0%

Cr $O_{4}^{2 -}$ $\to$ Cr³⁺
0%

Mn $O_{4}^{-}$ $\to$ MnO₂
0%

Cr₂ $O_{7}^{2 -}$ $\to$ 2Cr³⁺

In the reaction;

2Ag + 2H₂SO₄ $\to$ Ag₂SO₄ + 2H₂O + SO₂, H₂SO₄ acts as:

0%

Oxidizing agent
0%

Reducing agent
0%

Dehydrating agent
0%

None of the above

Which of the following shows the highest oxidation number in the combined state?

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Os
0%

Ru
0%

Xe
0%

All of the above

Equation that does not represent a redox reaction is-

0%

BaO₂ + H₂SO₄ $\to$ BaSO₄ + H₂O₂
0%

2BaO + O₂ $\to$ 2BaO₂
0%

2KClO₃ $\to2$ KCl + 3O₂
0%

SO₂ + 2H₂S $\to$ 2H₂O + 3S

In the preparation of chlorine from HCl; MnO₂ acts as:

0%

Catalytic agent
0%

Dehydrating agent
0%

Reducing agent
0%

Oxidising agent

Excess of KI reacts with CuSO₄ solution and then Na₂S₂O₃ solution is added to it. Which of the statement is incorrect in this reaction?

0%

Evolved I₂ is reduced
0%

CuI₂ is formed
0%

Na₂S₂O₃ is oxidised
0%

Cu₂I₂ is formed

In the equation,

N $O_{2}^{-}$ + H₂O $\to$ N $O_{3}^{-}$ + 2H⁺ + ne^-

n represents

0%

5
0%

1
0%

2
0%

3

Amount of oxalic acid present in a solution can be determined by its titration with KMnO₄ solution in the presence of H₂SO₄. The titration gives unsatisfactory result when carried out in the presence of HCl, because HCl:

0%

oxidises oxalic acid to carbon dioxide and water
0%

gets oxidised by oxalic acid to chlorine
0%

furnishes H⁺ ions in addition to those from oxalic acid
0%

reduces permanganate to Mn²⁺

KMnO₄ in acidic medium is always reduced to:

0%

Mn⁴⁺
0%

Mn²⁺
0%

Mn⁶⁺
0%

Mn

Reaction between acidified K₂Cr₂O₇ and iron (II) ions shown by the equation:

Cr₂ $O_{7}^{2 -}$ (aq) + 6Fe²⁺(aq) +14H⁺(aq) $\to$ 2Cr³⁺(aq) + 7H₂O(l) + 6Fe³⁺(aq)

The correct statement among the following is -

0%

Colour of the solution changes from green to blue
0%

Iron (II) ions are reduced
0%

Dichromate ions are reduced
0%

Hydrogen ions are reduced

The oxidation number of carbon in C₃O₂ and Mg₂C₃ are respectively:

0%

-4/3, +4/3
0%

+4/3, -4/3
0%

-2/3, +2/3
0%

-2/3, +4/3

Which metal exhibits more than one oxidation states?

0%

Na
0%

Mg
0%

Al
0%

Fe

The decomposition of KClO₃ to KCl and O₂ on heating is an example of:

0%

intermolecular redox change
0%

intramolecular redox change
0%

disproportionation or auto redox change
0%

none of the above

Among the following, In which iron has the lowest oxidation state?

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Fe(CO)₅
0%

Fe₂O
0%

K₄Fe(CN)₆
0%

FeSO₄.(NH₄)₂SO₄.6H₂O

Reducing agent among the following is -

0%

HNO₃
0%

KMnO₄
0%

H₂SO₄
0%

(COOH)₂

The equivalent mass of a reductant or an oxidant is given by:

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Eq. mass = $\frac{m o l a r m a s s o f r e d u c \tan t o r o x i d a n t}{n o . o f e l e c t r o n s l o s t o r g a i n e d b y 1 m o l e c u l e o f r e d u c \tan t o r o x i d a n t}$
0%

Eq. mass = $\frac{m o l a r m a s s}{v a l e n c e}$
0%

Eq. mass = $\frac{m o l a r m a s s}{t o t a l c h a r g e o n c a t i o n o r a n i o n}$
0%

All of the above

NaH+ H₂O $\to$ NaOH + H₂:

The correct statement for above mentioned reaction among the following is-

0%

H^- is oxidised
0%

Na⁺is reduced
0%

Both NaH and H₂O are reduced
0%

None of the above

When an acidified solution of ferrous ammonium sulphate is treated with KMnO₄ solution, the ion that gets oxidised is:

0%

Fe²⁺
0%

S $O_{4}^{2 -}$
0%

N $H_{4}^{+}$
0%

Mn $O_{4}^{-}$

In the reaction,

Cr₂ $O_{7}^{2 -}$ +14H⁺ + 6I^- $\to$ 2Cr³⁺ + 7H₂O + 3I₂,

Which element is reduced?

0%

I
0%

O
0%

H
0%

Cr

2Na₂S₂O₃+ I₂ $\to$ Na₂S₄O₆ + 2NaI,

the oxidation state of sulphur in tha above reaction:

0%

Decreases
0%

Increases
0%

Remain unchanged
0%

None of the above

In the aluminothermic process, aluminium acts as:

0%

an oxidising agent
0%

a flux
0%

a reducing agent
0%

a solder

Disproportionation reaction(s) among the following is/are represented by -

0%

Cl₂ + 2OH^- $\to$ ClO^- + Cl^- + H₂O
0%

Cu₂O(s) + 2H⁺ $\to$ Cu²⁺ + Cu(s) + H₂O
0%

2HCuCl₂ $\to_{water}^{Dilution with}$ Cu + Cu²⁺ + 4 Cl^- + 2H⁺
0%

All of the above

During a redox change, the oxidant K₂Cr₂O₇ is always reduced to:

0%

Cr⁵⁺
0%

Cr⁴⁺
0%

Cr³⁺
0%

Cr²⁺

The reaction,

3ClO^-(aq) $\to$ Cl $O_{3}^{-}$ (aq) + 2Cl^-(aq)

is an example of:

0%

oxidation reaction
0%

reduction reaction
0%

disproportionation reaction
0%

decomposition reaction

Oxidation state of +1 for phosphorus is found in:

0%

H₃PO₃
0%

H₃PO₄
0%

H₃PO₂
0%

H₄P₂O₇

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Practice Chemistry Quiz Questions and Answers

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Practice Chemistry Quiz Questions and Answers

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