Which one of the following pairs of substances will not produce hydrogen when reacted together?

• Copper and conc. nitric acid

• Ethanol and metallic sodium

• Magnesium and steam

• Phenol and metallic sodium

The hardness of water samle containing 0.002 mole of magnesium sulphate dissolved in a litre of water is expressed as

• 20 ppm

• 200 ppm

• 2000 ppm

• 120 ppm

When hydrogen peroxide is added to acidified potassium dichromate, a blue colour is produced due to formation of

• CrO₃

• Cr₂O₃

• CrO₅

• CrO${}_4^{2-}$

The pH of a neutral water is 6.5. Then the temperature of water

• is 25°C

• is more than 25°C

• is less than 25°C

• can be more or less than 25°C

Hydrogen peroxide when added to a solution of potassium permanganate acidified with sulphuric acid:

• forms water only

• acts as an oxidizing agent

• acts as a reducing agent

• produces hydrogen

The equilibrium molecular structure of hydrogen peroxide is :

• Planar as given below

  

• linear

• tetrahedral

• non-planar

The process used in conversion of triolein to tristearin is

• hydrolysis

• hydration

• hydrogenation

• dehydrogenation

188.

.... process is used for the removal of hardness of water.

• Calgon

• Baeyer

• Serpeck

• Hoope

What is the gas liberated when alkaline formaldehyde solution is treated with H₂O₂?

• CO₂

• O₂

• CH₄

• H₂

The products formed when heavy water is reacted with magnesium nitride, are

• NH₃, Mg(OH)₂

• NH₃, Mg(OD)₂

• ND₃, Mg(OH)₂

• ND₃, Mg(OD)₂