s-block-quiz-9

S-Block Quiz-9

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. Which alkaline earth metal nitride is volatile?

•  Be₃ N₂
•  Mg₃ N₂
•  Ca₃ N₂
•  None of these

Solution
(a) Except Be₃ N₂, rest all are non-volatile nitrides.  

Q2.Which is used in preparation of portland cement?

•  Limestone, clay and sand
•  Limestone, gypsum and sand
•  Limestone, gypsum and alumina
•  Limestone, clay and gypsum

Solution

(d) It is a fact.

Q3. The byproduct of Solvay process is: 

•  CO₂
•  CaCl₂
•  NH₃
•  CaCO₃

Solution
(b) An intermediate reaction in Solvay process gives CaCl₂. 

Ca(OH)₂+2NH₄ Cl⟶CaCl₂+2NH₃+2H₂ O

Q4. Sodium is manufactured by the electrolysis of a fused mixture of sodium and calcium chlorides in a steel cell using a graphite anode and an iron cathode. Calcium is not liberated since:

•  It belongs to a higher group in the periodic table
•  It combines with the liberated chlorine to form calcium chloride again
•  Its discharge potential under these conditions is higher than that of sodium
•  It is more readily fusible than sodium chloride

Solution
(c) It is a reason for given fact for given fact

Q5.Mg burns in CO to produce

•  MgO+CO
•  MgO₂
•  MgO+C
•  MgCO₃

Solution
  (c)MgO+C 

Q6. Several blocks of Mg are fixed to the bottom of a ship to:

•  Prevent action of water and salt
•  Prevent puncturing by under sea rocks
•  Keep away the sharks
•  Make the ship lighter

Solution
(d) Mg due to lightness and toughness is used in ships.  

Q7.Alkali metals act as

•  Good dehydrating agent
•  Good reducing agent
•  Good oxidising agent
•  None of these

Solution

(b) Alkali metals have only one electron in their ultimate shell, hence they can easily donate electron and act as reductant e.g.,

 Fe₂ O₃+6Na →2Fe+2Na₂ O

Q8.Pearl ash and caustic potash are chemically:

•  K₂ CO₃ and KOH
•  KOH and K₂ CO₃
•  Na₂ CO₃ and KOH
•  Na₂ CO₃ and NaOH

Solution
(a) Pearl ash is K₂ CO₃; caustic potash is KOH.  

Q9.In which of the following processes, fused sodium hydroxide is electrolysed at 330℃ temperature for extraction of sodium?

•  Castner’s process
•  Cyanide process
•  Down’s process
•  Both (b) and (c)

Solution

(a)Castner’s process

Q10. Potassium is kept in

•  Alcohol
•  Kerosene
•  Liquid ammonia
•  Water

Solution

(b) Alkali metals are highly reactive metals. They react with alcohol as

 2C₂ H₅ OH+2K→2C₂ H₅ OK+H₂ 

With water as 2K+2H₂ O→2KOH+H₂ 

With ammonia as K+(x+y) NH₃→[K(NH₃ )_x ]⁺+[e(NH₃ )_y ]^- ammoniated ammoniated cation electrons