REDOX AND EQUIVALENT CONCEPT QUIZ-17

REDOX AND EQUIVALENT CONCEPT QUIZ-17

Dear Readers,

The one subject in NEET which is candidates who can easily attain good marks is Chemistry. That's the reason, often, one doesn't pay notice and choose to compromise it. But if one wants to rank above others, the tip is to be thorough with NEET chemistry concepts. The understanding of reactions and definite basic understanding is what requires major attention in Chemistry but once done it only gets simpler from there. The main focus on the to-do list should be on getting a hang of the NCERT syllabus of NEET chemistry. .

Q1. Oxidation state of sulphur in Na₂ S₂ O₃ and Na₂ S₄ O₆

•  4 and 6
•  3 and 5
•  2 and 2.5
•  6 and 6

Solution

Q2.In alkaline condition KMnO₄ reacts as follows, 2KMnO₄+2KOH ⟶2K₂ MnO₄+H₂ O+O Therefore, its equivalent weight will be :

•  31.6
•  52.7
•  79.0
•  158.0

Solution
Mn⁽⁷⁺⁾ +e ⟶Mn⁽⁶⁺⁾ ∴ E=M/1 

Q3.  The reaction, Ag⁽²⁺⁾ (aq)+Ag(s)⇌2Ag⁺ (aq) is an example of

•   Reduction
•  Oxidation
•  Comproportionation
•  Disproportionation

Solution
The reaction, in which two or more species undergo reduction as well as oxidation to give a single species are called comproportionation reaction. This is reverse of disproportionation reaction. Ag⁽²⁺⁾ (aq)+Ag(s)⇌2Ag⁺ (aq)

Q4. The coefficients of I^-,IO₃^- and H⁺ in the redox reaction, I^-+ IO₃^-+H⁺→I₂+H₂ O in the balanced form respectively are

•  5, 1, 6
•  1, 5, 6
•  6, 1, 5
•  5, 6, 1

Solution

Q5.The colour of K₂ Cr₂ O₇ changes from red-orange to lemon-yellow on treatment with KOH(aq) because of :

•  Reduction of Cr(VI) to Cr(III)
•  Formation of chromium hydroxide
•  Conversion of dichromate into chromate ion
•  Oxidation of potassium hydroxide to potassium peroxide

Solution
  K₂ Cr₂ O₇+2KOH ⟶2K₂ CrO₄ (red-orange) (lemon-yellow)

Q6. Among NH₃,HNO_{(3,) N}aN₃ and Mg₃ N₂; the number of molecules having nitrogen in negative oxidation state is

•  1
•  2
• 3
•  4

Solution

Q7.Oxidation number of S in S₂ Cl₂ is :

•  +1
•  +6
•  Zero
•  -1

Solution
2 × a+2 × (-1)=0 ∴a= +1

Q8.The value of 'n' in the reaction Cr₂ O₇^(2-)+14H⁺+nFe⁽²⁺⁾ ⟶2Cr⁽³⁺⁾+nFe⁽³⁺⁾+7H² O will be

•  2
•  T3
•  6
•  7

Solution

Q9.100 mL of 0.1 M solution of a reductant is diluted to 1 litre, which of the following changes?

•  Molarity
•  Millimole
•  Milliequivalent
•  None of these

Solution
Milliequivalent [(W/Eq.wt.) × 1000] or millimole [(W/M) × 1000] do not change on dilution.

Q10. Manganese acts as strongest oxidising agent in the oxidation state

•  +7
•  +2
•  +4
• +5

Solution
Mn is stronger oxidising agent in +7 oxidation state. e.g., KMnO₄.