redox-and-equivalent-concept-quiz-7

Redox And Equivalent Concept Quiz-7

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. The compound that can work both as an oxidising and reducing agent is:

•  KMnO₄
•  H₂ O₂
•  Fe₂ (SO₄ )₃
•  K₂ Cr₂ O₇

Solution
(b) Oxygen in H₂ O₂ has ox.no. −1 which can increase or decrease.  

Q2.A group of methods of quantitative chemical analysis involving the measurement of volume of reacting substance is known as :

•  Gravimetric analysis
•  Volumetric analysis
•  Both (a) and (b)
•  None of the above

Solution

(b) It is definition of volumetric analysis.

Q3. When K₂ Cr₂ O₇ is converted into K₂ CrO₄, the change in oxidation number of chromium is 

•  0
•  5
•  7
•  9

Solution
(a) Let oxidation state of Cr in K₂ Cr₂ O₇=x (+1×2)+2x+(-2×7)=0 

 or +2+2x-14=0 

 ∴ x=+6 Let oxidation state of Cr in K₂ CrO₄=x +1×2+x+(-2×4)=0 2+x-8=0 x=6 

 ∴ Change in oxidation state of Cr is zero when it changes from K₂ Cr₂ O₇ to K₂ CrO₄.

Q4. NO₃^- ions are converted to NH₄⁺ ions by a suitable reactant. The equivalent mass of NO₃^- and NH₄⁺ are :

•  7.75, 2.25
•  7.75, 7.75
•  2.25, 7.75
•  2.25, 2.25

Solution

Q5. During a redox titration involving a solution containing Fe²⁺ ions against MnO₄^- in the presence of excess of H⁺ ions, the number of electrons that gets transferred is

•  6
•  5
•  4
•  2

Solution
 

 

Q6. In the reaction, SO₂+2H₂ S⟶3S+2H₂ O, the substance oxidised is

•  H₂ S
•  SO₂
•  S
•  H₂ O

Solution


 

Q7.As the oxidation state for any metal increases, the tendency to show ionic nature:

•  Decreases
•  Increases
•  Remains same
•  None of these

Solution

(a) Tendency to lose more electron for cation decreases.

Q8.Addition of zinc powder to CuSO₄ solution precipitates copper due to :

•  Reduction of Cu²⁺
•  Reduction of SO₄^2-
•  Reduction of Zn
•  Hydrolysis of CuSO₄

Solution
(a) Cu²⁺+2e ⟶Cu  

Q9.Oxidation number of Fe in K₃ [Fe(CN)₆] is :

•  +2
•  +3
•  +4
•  +1

Solution

(b) 3 × 1+a+6 × (-1)=0 ∴a= +3

Q10. Oxidation number of S in S₂ O₃^2-is :

•  +2
•  -2
•  4
•  Zero

Solution

(a) 2 × a+3 × (-2)= -2 ∴a= +2