Chemistry Questions Answers

• 57. Identify the wrong statement in the following

  1. Atomic radius of the elements increases as one moves down the first group of the periodic table
  2. Atomic radius of the elements decreases as one moves across from left to right in the 2nd period of the
  3. Amongst isoelectronic species, smaller the positive charge on the cation, smaller is the ionic radius
  4. Amongst isoelectronic species, greater the negative charge on the anion, larger is the ionic radius

  Answer :

  Option C

• 58. A catalyst is a substance which
  

  1. increases the activation energy
  2. increases the rate of reaction and increases the equilibrium concentration of products
  3. changes the equilibrium of a reaction so that the concentration of the product increases
  4. hastens the attainment of equilibrium

  Answer :

  Option D

• 59. Air contains maximum amount of
  

  1. oxygen
  2. nitrogen
  3. hydrogen
  4. carbon dioxide

  Answer :

  Option B

• 60. Which gas is used to manufacture vanaspati from vegetable oil is

  1. carbon dioxide
  2. nitrogen
  3. oxygen
  4. hydrogen

  Answer :

  Option D

• 61. Air is a

  1. compound
  2. colloid
  3. element
  4. mixture

  Answer :

  Option D

• 62. Homo nuclear molecules contain ?

  1. polar bond
  2. covalent bond
  3. ionic bond
  4. coordinate bond

  Answer :

  Option B

• 63. Permanent hardness of water is due to the presence of ?

  1. Magnesium bicarbonate
  2. Calcium bicarbonate
  3. Sodium bicarbonate
  4. Calcium sulphate

  Answer :

  Option D