CHEMISTRY CHEMICAL EQUILBRIUM QUIZ-1

CHEMISTRY CHEMICAL EQUILBRIUM QUIZ-1

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.

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Q1. For the following reaction in gaseous phase CO+1/2 O₂⟶CO₂
K_c⁄K_p is

•  RT^1⁄2
•  RT^-1⁄2
•  (RT)
•  (RT)^-1

Solution
(a) K_p=K_c(RT)^{(∆n_g )} ∆n_g=1-1.5=-0.5 K_p=K_c (RT)^((-1)⁄2)=K_c/(RT)^(1⁄2) ∴ K_c/K_p =(RT)^(1⁄2)

Q2.The change in pressure will not affect the equilibrium constant for

•  N₂+3H₂⇌2NH₃
•  PCl₅⇌PCl₃+Cl₂
•  H₂+I₂⇌2HI
•  All of these

Solution
(d) The change in pressure will not affect the equilibrium constant. Equilibrium constant changes with change in temperature.

Q3.  For which salt the pH of its solution does not change with dilution?

•  NH₄Cl
•  CH₃ COONH₄
•  CH₃COONa
•  None of these

Solution
b) pH of salts of weak acid and weak base is derived by the relation :[H⁺ ]=√(K_H )=√(K_w/(K_a∙K_b ))

Q4. In a reversible reaction two substance are in equilibrium. If the concentration each one is doubled, the equilibrium constant will be

•  Reduced to one fourth of its original value
•  Reduced to half of its original value
•  Constant
•  Doubled

Solution
c) The equilibrium constant does not depend on concentration, when reversible reaction at equilibrium hence, equilibrium constant will be constant.

Q5.The reaction which proceeds in the forward direction is :

•  Fe₂O₃+6HCl=2FeCl₃+3H₂O
•  SnCl₄+Hg₂Cl₂=SnCl₂+2HgCl₂
•  NH₃+H₂O+NaCl=NH₄Cl+NaOH
•  2CuI+I₂+4K⁺ =2Cu⁽²⁺⁾+3KI

Solution
 (a) It is an acid-base reaction; Rest all occurs in reverse direction.

Q6.H₃BO₃ is:

•  Monobasic and weak Lewis acid
•  Monobasic and weak Bronsted acid
•  Monobasic and strong Lewis acid
•  Tribasic and weak Bronsted acid

Solution
(a) H₃BO₃ accepts OH^- ions to act as weak monobasic Lewis acid. H₃BO₃+H₂O⟶B(OH)₄^-+H⁺;K_a=10^(-9)

Q7.The equilibrium constant, K for the reaction 2HI(g)⇌H₂ (g)+I₂ (g) At room temperature is 2.85 and that at 698 K, it is 1.4×10^(-2). This implies that

•  HI is resonance stabilised
•  HI is exothermic compound
•  HI is stable at room temperature
•  HI is less stable than H₂ and I₂

Solution
d) Decrease of K with rise of temperature means that the forward reaction is exothermic. As the given reaction is exothermic, energy of HI is greater or stability is less than H₂and I₂

Q8.The aqueous solution of AlCl₃ is acidic due to the hydrolysis of

•  Aluminum ion
•  Chloride ion
•  Both aluminium and chloride ion
•  None of the above

Solution
(a) Aqueous solution of AlCl_3 is acidic due to the hydrolysis of aluminium ion AlCl₃ →^Hydrolysis Al(OH)₃+H⁺

Q9.The pH of blood is maintained by CO₂ and H₂CO₃ in the body and chemical constituents of blood. This phenomenon
is called:

•  Colloidal
•  Buffer action
•  Acidity
•  Salt balance

Solution
(b) A buffer of H₂CO₃ and HCO₃^- is formed.

Q10. 10. The pH of a solution obtained by mixing 50 mL of 1 N HCl and 30 mL of 1 N NaOH is [log⁡2.5=0.3979]

•  3.979
•  0.6021
•  12.042
•  1.2042

Solution
b) Concentration of mixture