ECAT Pre Engineering MCQ Test With Answer for Chemistry Full Book

The positive ion is always smaller than the neutral atom while the negative ion is always bigger than the neutral atom. The atomic and ionic radii of Na, F, Na⁺, F^-are in ppm

• Na F Na⁺ F^-
  157 72 95 136
  A
• Na F Na⁺ F^-
  157 95 172 136
  B
• Na F Na⁺ F^-
  72 95 136 157
  C
• Na F Na⁺ F^-
  157 136 95 72
  D

Which of the following correctly describes the process occurring at the electrodes when molten NaCl is electrolyzed:

• No reaction at anode, reduction at cathode. A
• No reaction at cathode, oxidation at anode. B
• Oxidation at anodes, reduction at cathode. C
• Oxidation at cathode, reduction at anode. D

London dispersion forces are also called:

• Hydrogen bonding. A
• Debye forces B
• Van der Waal's forces C
• Instantaneous dipole-induced dipole forces. D

Caustic soda is obtained by electrolysis of conc. aqueous solution of NaCI in a cell called

• Daniell's cell A
• Nelson's cell B
• Down's cell C
• Voltaic cell D

Partial pressure of a solution component is directly proportional to its mole fraction. This statement is known as

• Henry's law A
• Raoult's law B
• Distribution law C
• Ostwald's dilution law D

Which one of the following reaction rate is effected by the light

• 
  A
• 
  B
• 
  C
• 
  D

The addition of a catalyst to a reaction changes the

• Enthalpy A
• Entropy B
• Nature of reactants C
• Energy of activation D

If carbon dioxide is bubbled through solution of Grignard's reagent in ether and the resultant product is reacted with hydrochloric acid, it gives

• An alkane A
• Al alcohol B
• A carboxylic acid C
• An aldehyde D

Hydrolysis of Grignard's reagent gives:

• Alcohol A
• Halide B
• Alkyl C
• Alkane D

A compound is soluble in conc. H₂SO₄, it does not decolourise bromine in carbon tetrachloride but is oxidized by chromic anhydride in aqueous sulphuric acid within two seconds, turning orange solution to blue, green and then opaque. The original compound is

• Primary alcohol A
• Tertiary alcohol B
• alkene C
• ether D

The best electrode used in salt bridge is KCl. Which other electrolyte an also be used for the purpose :

• NaCl A

• NH₄NO₃

  B

• KNO₃

  C

• NaNO₃

  D

Pakistan in the beginning was a country :

• Industrial A
• Chemical B
• Agrarian C
• Technologies D

Weakest acid among the followings is

• Acetic acid A
• Phenol B
• Water C
• Acetylene D

Organic synthetic or man made polymers are plastics, rubber and fibre. Which is not a synthetic polymer

• Silk A
• Polyester B
• Polyvinyl chloride C
• Nylon D

How should condition be changed to prevent the volume of a given gas from expanding whine its mass is increased ?

• Temperature is lowered and pressure is increased A
• Temperature is increasedand pressure is lowered B
• Temperature and pressure both are lowered C
• Temperature and pressure both are increased D

Metals like Fe, Mg, Al, Cr, Zn have more negative reduction potentials that is whey

• These don't react with steam A
• These react very slowly with steam to liberate H₂gas B
• These react rapidly with steam to produce the metallic oxides and liberate H₂gas C
• These react with cold water violently D

Number of neutrons in heavy hydrogen atom is

• 0 A
• 1 B
• 2 C
• 3 D

Sodium is never found free in nature because of its

• Chemical reactivity A
• Small ionic size B
• Small atomic volume C
• None of these D

The boiling point of NH₃is maximum among the hydrides of group V elements due to

• Enhanced electronegative character of Nitrogen A
• Pyramidal structure of NH₃ B
• Very small size of Nitrogen C
• Enhanced electropositive character of Nitrogen D

Which of the following oxides is amopheric in character?

• CaO A
• CO₂ B
• SiO₂ C
• SnO₂ D

How much pesticides have been synthesized at present?

• Four thousands A
• Six thousands B
• Eight Thousands C
• Ten thousands D

The acid showing salt like character in aqueous solution is

• Acetic acid A
• Benzoic acid B
• Formic acid C
• α - Aminoacetic acid D

The increase in size of the anion is due to:

• Increase in electron-electron repulsion A
• Increase in valence shell electrons. B
• Decrease in valence shell electrons. C
• Both (a) and (b). D

• Initial concentration of reaction A
• Initial concentration of products B
• Final concentration of products C
• Order of the reaction D

I-A group elements are called:

• Alkali-metal A
• alkaline earth metals B
• Halogens C
• Chalocogens D

Phosphorous helps the growth of

• Root A
• Leave B
• Stem C
• Seed D

Which of the following is not fatty acid?

• Propanoic acid A
• Acetic acid B
• Phthalic acid C
• Butanoic acid D

The compound with cyclic hexamer is

• HF A
• HCl B
• HBr C
• HI D

When ethylene glycol is heated with acidified potassium permanganate, the main organic compound obtained is

• Oxalic acid A
• Glyoxal B
• Formic acid C
• Ethanol D

A compound contains 75% carbon and 25% hydrogen, by mass. What is the molecular formula of the compound/

• C₃H₈ A
• CH₄ B
• C₂H₄ C
• C₂H₆ D