ECAT Pre Engineering MCQ Test With Answer for Chemistry Full Book

Which of the following organic compounds exhibits positive Fehling test as well as iodoform test?

• Methanal A
• Ethanol B
• Propanone C
• Ethanal D

Noble gases in the atmosphere are

• 4% A
• 3% B
• 2% C
• 1% 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

Monosubstituted benzene can have disubstitution at position

• ortho A
• meta B
• para C
• a, b, c D

S_N1 reaction of alkylhalides leads to

• Retention of configuration A
• Recemisation B
• Inversion of configuration C
• None of these D

3-d series elements are present in:

• First period A
• Second Period B
• Third period C
• 4th period D

Evaporation of water is possible at:

• Above 100°C A
• 0°C B
• 100°C C
• At all temperature D

In electrolytic cells, the chemical changes may be :

• Either spontaneous or non-spontaneous A
• Always spontaneous B
• Always non-spontaneous C
• More spontaneous and less non-spontaneous. D

In physical and chemical properties, transition elements show

• Similarities A
• Dissimilarities B
• Both of these C
• Somestimes similarities, sometimes dissimilarities D

Halogens on treating with silver salts of acids give

• Alcohol A
• Ester B
• Phenol C
• Alkyl halide D

In passage of electricity through aqueous solution of AgNO₃silver dissolves at anode to form Ag⁺, the electrodes are

• Silver metal A
• Pt metal B
• Graphite C
• Copper metal D

An electrophile may be

• Positive A
• Negative B
• Neutral C
• Both c and a D

Which species represented by the following formula has the largest radius

• P^3- A
• Cl^- B
• A_r C
• K⁺ D

The state of hybridization of carbon atom in methane is:

• sp³ A
• sp² B
• sp C
• dsp² D

• 2, 3-dimethylbutane A
• 2, 3-methylbutane B
• 2-dimethylbutane C
• Dimethylbutane D

A sequence of how many nucleotides in massenger RNA makes a codon for an amino acid

• Three A
• Four B
• One C
• Two D

The order of frequency of the following radiations unltraviolet, visible, infrared and microwave is

• Microwave > infrared > visible > ultraviolet A
• Visible > ultraviolet > microwave > infrared B
• Ultraviolet > visible > infrared > microwave C
• Infrared > microwave > ultraviolet > visible D

Heat absorbed or released during the chemical reaction of physical process at constant pressure is equal to

• 
  A
• 
  B
• 
  C
• 
  D

The function of salt bridge is :

• To increase movement onions. A
• To increase the emf of cell. B
• To decrease the temperate C
• To maintain electrical neutrality D

DNA is a polynucleic acid. The monomer is known as a nucleotide. What is not the component of the nucleoptide

• Phosphate group A
• Deoxy ribose sugar B
• Uracil base C
• Adenine base D

A beaker contains 9 grams of water. The number of H atoms is

• 6.02 x 10²³ A
• 3.01 x 10²³ B
• 6.02 x 10²⁴ C
• 3.01 x 10²⁴ D

Posphorus belongs to a group

• III-A A
• IV-A B
• V-A C
• VI-A D

The compound prepared by a substitution reaction of benzene is

• Acetophenone A
• Glyoxal B
• Cyclohexame C
• Hexabromo cyclohexane D

The ratio of the ionization energy of H and Be³⁺is

• 1 : 1 A
• 1 : 3 B
• 1 : 9 C
• 1 : 16 D

The general formula of amino acids is

• 
  A
• 
  B
• 
  C
• 
  D

The term ebullioscopy is used for

• Depression of freezing point A
• Elevation in boiling point B
• Lower of vapour pressure C
• None of the above D

Stainless steel contains Cr upto

• 12% A
• 18% B
• 10% C
• 5% D

Which is the transition element among the following

• B A
• Al B
• Cu C
• Cs D

The element caesium bears resemblance with

• Ca A
• Cr B
• Rubidium C
• None of the above D

Hydrolysis of potassium acetate produces

• Acidic solution A
• Neutral solution B
• Basic solution C
• None of these D