ECAT Pre Engineering Chemistry Chapter 8 MCQ Test With Answer

The optimum conditions of temperature and pressure to get maximum NH₃form N₂and H₂gases is

• 2000°C and 10 atmosphere A
• 0°C and 1 atmosphere B
• 400°C and 200-300 atmosphere C
• 200°C and 100 atmosphere D

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

ph of the buffer CH₃COOh + CH₃COONa is 3.76. If the mixture contains 1 molar acetic acid and 0.1 molar sodium acetate, then pKa of this buffer is

• 3.76 A
• 4.76 B
• 5.76 C
• 6.76 D

In the particular reaction for the valueK_{c 1 x}10^-25which statement is correct :

• Almost forward reaction is completed. A
• Amount of reactant is negligible as compared to product. B
• Amount of product is negligible as compared to reactant. C
• Amount of product is equal to amount of reactant. D

K_avalue of HF acid is 6.7 x 10^-15the acid is a

• Weak acid A
• Moderately strong acid B
• Strong acid C
• Very weak acid D

K_spvalue for PbSO₄= 1.8 x 10^-8mole²dm^-6. The maximum concentration of Pb⁺⁺ions is

• 1.34 x 10^-4mole dm^-3 A
• 1.8 x 10^-4 B
• 3.6 x 10^-16mole dm^-3 C
• 1.0 x 10^-8mole dm^-3 D

2SO₂ + O₂ ⇌ 2SO₂ H= 188KJ mole^-1

Which statement about following equilibrium is correct :

• The value ofK_pfalls with arise in temperature. A
• The value ofK_pis equal tok_c. B
• The value ofK_pfalls with the increase pressure. C
• Adding V₂O₅ catalyst increase the equilibrium yield of Sulphur trioxide.
  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

Which of the following is a characteristic of a reversible reaction?

• It never proceeds to completion A
• It can be influenced by a catalyst B
• It proceeds only in the forward direction C
• Number of moles of reactants and products are equal D

In a lime kiln, to get higher yield of CO₂, the measure that can be taken is

• To main high temperature A
• To pump out CO₂ B
• To remove Cao C
• To add more CaCO₃ D

• Moles per dm³ A
• Partial pressures B
• Number of moles C
• Mole fractions D

Under what condition of temperature and pressure the formation of atomic hydrogen from molecular hydrogen will be favourd

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

Base buffer solution can be prepared by mixing

• Weak acid and its salt A
• Strong acid and its salt with weak base B
• Weak base and its salt with strong acid C
• Strong base and its salt with weak acid D

The ph of 10-3 mole dm-3 of an aqueous solution of H₂SO₄ is :

• 3.0

  A

• 2.7

  B
• 2.0 C

• 1.5

  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

An aqueous solution is neutral when its

• pH = 14 A
• pH = zero B
• pH = 7 C
• Kw = 10^-7 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

The value of K_pis greater than K_cfor a gaseous reaction when

• Number of molecules of products is greater than the reactants A
• Number of molecules of reactants is greater than those of products B
• Number of molecules of reactants and products equal C
• Catalyst is added D

• Reversible reaction A
• Irreversible reaction B
• Spontaneous reaction C
• None of these D

The correct relation b/wK_{c and}K_{p is :}

• K_p = K_c[P/N] ^Δn

  A

• K_{c =} K_p(RT) ^Δn

  B

• K_{p =} K_c(RT) ^Δn

  C

• K_{p =} K_c(RT) ^Δn

  D

Which one of the following is a buffer

• HCI + NaCI solution A
• CH₃COOH + CH₃COONH₄solution B
• H₂SO₄+ CaSO₄solution C
• CH₃COOH + CH₃COONa D

Units of Kw are

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

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

Almost forward reaction is complete when value of k_{c :}

• Neither larger nor very small. A
• Very small. B
• Very large. C
• Negligible. D

• Shift reaction toward forward direction A
• Shift reaction backward B
• Lower the value of K_c C
• No change in reaction D

Which statement about the following equilibrium in correct?

2SO_{2 (g)}+ O_2(g)---------------2sO_3(g)H= - 188.3 KJ mol-1

• T value of K_{p falls witha rise in temperate.} A
• The value of K_{p falls withincreasing pressure}
  B
• Adding V_2O5catalyst increase the equilibrium yield of sulfur trioxide
  C
• The value of K_{p is equal to}K_p D
• 
  
  E

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

pH of 0.1 molar HCl solution is

• 1 A
• zero B
• 13 C
• 14 D

pKb value of NH₄OH is 4.74. If the concentration of NH₄OH is 1 molar containing 0.1 molar NH₄Cl, then pH of this buffer will be

• 3.74 A
• 10.26 B
• 4.74 C
• 9.26 D