ECAT Pre Engineering Chemistry Chapter 8 MCQ Test With Answer

A buffer of a 0.09 molar acetic acid and 0.11 molar sodium acetate has pH = 4.83. If 0.01 mole NaOH in 1 dm³of the buffer solution is added, then pH of the buffer becomes

• 4.74 A
• 4.92 B
• 5.0 C
• 4.0 D

Which of the following favours the reverse reaction in chemical equilibrium?

• Increasing the concentration of the reactant A
• Removal of the least one of the products at regular intervals B
• Increasing the concentration of one or more of the products C
• None of these D

• 0.60 A
• 1.67 B
• 0.66 C
• 2.6 D

An excess of aqueous silver nitrate is added to aqueous barium chloride and precipitate is removed by filtration. What are the main ions in the filtrate

• 
  A
• 
  B
• 
  C
• 
  D

Which one of the following is not a buffer

• H₂CO₃+ NaHCO₃solution A
• H₃PO₄+ NaH₂PO₄solution B
• Hl + Nal solution C
• NH₄OH + NH₄CI solution D

An excess of aqueous silver nitrate is added to aqueous barium chloride and precipitate is removed by filtration. What are the main ion in filtrate?

• Ag⁺ and NO_3- only

  A

• Ag⁺ and Ba² and NO^-3

  B

• Ba² and NO^-3

  C

• Ba² and NO^-3 and Cl-

  D

0.1 MHCI has pH = 1.0, it is about 100 times stronger than acetic acid. Then pH of acetic acid will be

• 0.1 A
• 2.0 B
• 1.3 C
• 3.0 D

• Low pressure A
• High pressure B
• High temperature C
• High concentration of SO₂ D

N₂ +3H₂⇌ 2NH_{3 + Heat for above equation, themaximum product will be obtained at :}

• Low temperature at high pressure. A
• High temperature and low pressure. B
• High temperature and high pressure. C
• Low temperature at low pressure. D

If the difference of pKa values of the two acids is 2, then

• Acid with smaller pKa is 10 times stronger acid A
• Acid with greater pKa is 10 times stronger acid B
• Acid with smaller pKa is 100 times stronger acid C
• Acid with greater pKa is 100 times stronger acid D

• Total pressure A
• Amount of A₂and B₂ B
• Temperature C
• Catalyst D

• The value of K_pfalls with rise in temperature A
• The value of K_pfalls with increasing pressure B
• Addition of V₂O₅catalyst increase the concentration of SO₃ C
• The value of K_pis equal to K_c D

For what value ofK_{c almost forward reaction is complete :}

• K_{c =} 10³⁰

  A

• K_{c =} 10^-30

  B

• K_{c =} 0

  C

• K_{c =} 1

  D

Which of the following solution have zero pH

• 1 M HCI A
• MH₂SO₄ B
• 0.1 M HNO₃ C
• 1 M CH₃COOH D

In which of the following cases, the reaction goes farthest to completion

• K = 10³ A
• K = 10^-2 B
• K = 10 C
• K = 10⁰ D

• 450°C A
• 250°C B
• 850°C C
• 1000°C D

Product of concentration of ions raised to the power equal to the co-efficient of ions in balanced equation for saturated solution of a salt is called

• Ionic product A
• Equilibrium constant K_c B
• K_w C
• Solubility product (K_sp) D

The solubility product of AgCl is 2.0 x 10^-10mol²dm^-6The maximum concentration of Ag⁺ions in the solution is

• 2.0 x 10^-10mol dm^-3 A
• 1.41 x 10^-5mol dm^-3 B
• 1.0 x 10^-10mol dm^-3 C
• 4.0 x 10^-20mol dm^-3 D

The relation between Kc and Kp is

• 
  A
• 
  B
• 
  C
• 
  D

A chemical reaction A---------->B is said to be in equilibrium when :

• Rate of transformation of A to B is equal to B to A. A
• 50% reactant has been changed to B. B
• Conversion of A to B is 50% complete C
• Complete conversion of A to B has taken place. D

• 1 A
• 10 B
• 5 C
• 0.33 D

Units of Kw are

• Mole dm^-3 A
• Mole²dm^-3 B
• Mole²dm^-6 C
• Mole²dm^-3 D

Hydrogen gas and iodine vapours combine to form Hl at 425°C, the same composition of mixture is present if we start with decomposition of Hl. It suggests

• A static equilibrium A
• Law of mass action B
• A dynamic equlibrium C
• Irreversible reaction D

When a weak acid is dissolved in water or a weak base dissolved in water, then in both cases the conjugate acid base pair is produced. The ionization constants K_aand K_bof a pair are related with each other as

• K_a= K_b A
• K_a. K_b= K_w B
• K_a. K_w= K_b C
• K_b. K_w= K_a D

• Temperature is increased A
• Pressure is increased B
• HCl is added C
• HCl is removed D

A solution has pH = 0, its H⁺ion concentration is

• 1 x 10^-14 A
• 1 x 10¹⁴ B
• 1 x 10¹ C
• 1 D

• [A] = [B] A
• [A] < [B] B
• [B] = [C] C
• [A] > [B] D

• Favour the formation of N₂O₄ A
• Favour the decomposition of N₂O₄ B
• Not alter the equilibrium C
• Stop the reaction D

The solubility of PbF₂is 2.6 x 10^-3mole dm^-3 then its solubility product is

• 2.6 x 10^-3 A
• 6.76 x 10^-6 B
• 5.2 x 10^-6 C
• 7.0 x 10^-8 D

• High temperature and low pressure A
• Low temperature and low pressure B
• Low temperature and high pressure C
• High temperature and high pressure D