Chemistry Questions and Answers

1.

Which one of the following elements is essential for construction is nuclear reactors

   A.) Cobalt
   B.) Zirconium
   C.) Nickel
   D.) Tungsten

Answer: Option 'B'

Zirconium

2.

Natural Rubber is a Polymer of

   A.) butadiene
   B.) 2methyl-1,3butadiene
   C.) ethylene
   D.) isoprene

Answer: Option 'D'

Natural Rubber is a Polymer derived from Isoprene. 

  • Natural rubber is an addition polymer that is obtained as a milky white fluid known as Latex from a Tropical Rubber Tree.

3.

A mixture of ethyl alcohol  and water can be seperated  by 

   A.) using a seperating funnel
   B.) fractional distillation
   C.) sublimation
   D.) evaporation

Answer: Option 'B'

Fractional distillation is the process of seperation of a mixture of two or more liquids into the different fractions, which differ fairly widely in their boiling points. The liquid with a lower boiling point will be vaporized first and hence would be the distillate (first fraction). Eg. Ethyl alcohol has a boiling point of 78.1ºC and water 100ºC. When a mixture of these two liquids is heated, alcohol vaporizes first and is collected separately as the distillate. 

4.

When formaldehyde and potassium hydroxide are heated , we get 

   A.) Methane
   B.) Methyl alcohol
   C.) Acetylene
   D.) Ethyl formate

Answer: Option 'B'

Methyl alcohol

5.

Which one of the following laws explain the formation of carbon monoxide and carbon dioxide from carbon and oxygen

   A.) Laws of conservation of mass
   B.) Laws of multiple proportion
   C.) Laws of reciprocal proportions
   D.) Law of definite proportions

Answer: Option 'B'

Laws of multiple proportion

6.

Which one of the following is not a mixture

   A.) milk
   B.) mercury
   C.) cementair
   D.) air

Answer: Option 'B'

mercury

7.

Which of the following is the strongest acid?

   A.) ClCH2COOH
   B.) BrCH2COOH
   C.) FCH2COOH
   D.) ICH2COOH

Answer: Option 'C'

FCH2COOH is the strongest acid out of all .Since the electron withdrawing inductive effect (-I effect) of the halogens decreases in the order

F>Cl> Br> I , therefore the acidic strength of the α- halo acids decreases in the same order.

FCH2COOH  >  ClCH2COOH   >   BrCH2COOH   >   ICH2COOH.

8.

Cutting and peeling of onion brings tears to the eyes because of the presence of _____ ?

   A.) Carbon
   B.) Sulfur
   C.) Amino acid
   D.) Fat

Answer: Option 'B'

Cutting and Peeling of onion brings Tears to the eyes because of presence of Sulphur in the cell.

9.

Which is the gas used for making vegetables and vanaspathi from vegetable oils?

   A.) Argon
   B.) Hydrogen
   C.) Nitrogen
   D.) Helium

Answer: Option 'B'

Hydrogen gas is used for making vegetables and vanaspathi from vegetable oils.

As it is colourless, odourless, tasteless, flammable gaseous substance, it is added to oils to make them more solid or spreadable.

The use of hydrogenation helps to prolong the shelf life of the food and maintain flavour stability.

10.

The Kinetic energy of gas molecules

   A.) is unaffected by temperature variations
   B.) decreases with increase of temperature
   C.) increases with decrease of temperature
   D.) increases with increase of temperature

Answer: Option 'D'

increases with increase of temperature

11.

In the making of jewels, gold is usually mixed with 

   A.) copper
   B.) aluminium
   C.) tin
   D.) zinc

Answer: Option 'A'

copper

12.

Who present the theory of radioactive disintegration

   A.) Thomson and Rutherford
   B.) Hahn and strassman
   C.) Soddy and Fajan
   D.) Rutherford and Soddy

Answer: Option 'D'

Rutherford and Soddy

13.

The atoms of the elements which have same number of neutrons are called

   A.) Isotones
   B.) Isobars
   C.) Isotopes
   D.) None of these

Answer: Option 'A'

Isotones

14.

Alum is used 

   A.) as an analgesic
   B.) in the purification of water
   C.) as a fertilizer
   D.) as a disinfectant

Answer: Option 'B'

​in the purification of water

15.

Which of the following is used to preserve specimens in the biology laboratory?

   A.) Formaldehyde
   B.) Benzaldehyde
   C.) Phenol
   D.) Acetic acid

Answer: Option 'A'

A 40% solution of Formaldehyde known as Formalin is used in the preservation of biological specimens because of its hardening action on proteins. 

16.

One of the ingredients of the paste on the side of a match box is 

   A.) Phosphorus pentaoxide
   B.) Phosphorus trichloride
   C.) Phosphorus trisulphide
   D.) Phosphorus trioxide

Answer: Option 'C'

The paste applied to the side of a match box is a mixture of phosphorus trisulphide, glass powder (or sand) to cause friction and glue (binding material)

17.

The metal which reacts most violently with with cold water is

   A.) magnesium
   B.) potassium
   C.) calcium
   D.) sodium

Answer: Option 'B'

potassium

18.

In addition to nitric acid, another acid which may render iron passive is 

   A.) chromic acid
   B.) oxalic acid
   C.) acetic acid
   D.) citric acid

Answer: Option 'A'

Passivity of iron is due to formation of an extremely thin and impervious film of ferrosoferric oxide [Fe3(O4)]Fe3O4on the surface of iron. Chromic acid, being a powerful oxidising agent (like nitric acid ) renders iron passive. 

19.

A bond formed by the transfer of electrons between atoms of the elements is called

   A.) Co-ordinate bond
   B.) Ionic bond
   C.) Covalent bond
   D.) Hydrogen bond

Answer: Option 'B'

Ionic bond

20.

Temporary hardness is due to the presence of 

   A.) magnesium sulphate
   B.) calcium bicarbonate
   C.) Calcium carbonate
   D.) calcium sulphate

Answer: Option 'B'

Temporary hardness is due to the presence of soluble bicarbonates of calcium and magnesium in water. Permanent hardness is due to the presence of sulphates and chlorides of calcium and magnesium.

 

 


Chemistry Questions and Answers Download Pdf