redox-and-equivalent-concept-quiz-4

Redox And Equivalent Concept Quiz-4

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 oxidation state shown by silicon when it combines with strongly electropositive metals is

•  -2
•  -4
•  +4
•  +2

Solution
(b) Si has 4 electrons in its valence shell. When it reacts with strongly electropositive metal like Na, Mg, K etc., it gives 4 electrons and its oxidation state in this case is -4.  

Q2.In which of the following oxidation number of chlorine is +5?

•  HClO
•  HClO₂
•  HClO₃
•  HClO₄

Solution

(c) 1+a+3 × (-2)=0 ∴a= +5

Q3. Oxidation state of +1 for phosphorus is found in : 

•  H₃ PO₃
•  H₃ PO₄
•  H₃ PO₂
•  H₄ P₂ O₇

Solution
(c) 3 × 1+a+2 × (-2)=0 ∴a= +1

Q4. In the reaction of O₃ and H₂ O₂, the later acts as :

•  Oxidising agent
•  Reducing agent
•  Bleaching agent
•  Both oxidising and bleaching agent

Solution
(a) O₃+H₂ O₂ ⟶H₂ O+2O₂;H₂ O₂ is reduced.

Q5.The oxidation number of Cr in K₂ CrO₄ is

•  +3
•  -6
•  +6
•  -3

Solution
  (c) Let the oxidation number of Cr in K₂ CrO₄ is x. 2(+1)+x+4(-2)=0 2+x-8=0 x=+6  

Q6. Magnesium reacts with acids producing hydrogen and corresponding magnesium salts. In such reactions magnesium undergoes :

•  Oxidation
•  Reduction
•  Neither oxidation nor reduction
•  Simple dissolution

Solution
(a) Mg+2HCl ⟶MgCl₂+H₂.  

Q7.In the reaction, Zn+2H⁺ +2Cl^- ⟶Zn²⁺ 2Cl^- +H₂, the spectator ion is :

•  Cl^-
•  Zn²⁺
•  H⁺
•  All of these

Solution

(a) The species present in solution but does not take part in the reaction and are also omitted while writing the potential redox change are called spectator ion.

Q8.When potassium permanganate is titrated against ferrous ammonium sulphate, the equivalent weight of potassium permanganate is :

•  Molecular weight/10
•  Molecular weight/5
•  Molecular weight/2
•  Molecular weight

Solution
(b) Mn⁷⁺+5e ⟶Mn²⁺ Fe²⁺ ⟶Fe³⁺+e  

Q9.Which reaction involves neither oxidation nor reduction?

•  CrO₄^2- ⟶Cr₂ O₇^2-
•  Cr ⟶CrCl₃
•  Na ⟶Na⁺
•  2S₂ O₃^2- ⟶S₄ O₆^2-

Solution

(a) Ox.no. of Cr on both side is +6

Q10. The reaction; KI+I₂ ⟶KI₃ shows :

•  Oxidation
•  Reduction
•  Complex formation
•  All of these

Solution

(d) It is a complexation reaction involving reduction of I₂ and oxidation of KI.