Question Discussion & Solution

The correct option is 2 i.e. Sodium Carbonate

Key Points

• Sodium Carbonate is also known as washing soda it is a salt of carbonic acid.
• Sodium carbonate can be manufactured by Solvay's process.
• It is used for treating hard water and industrial detergent mixtures.
• The aqueous solution of sodium carbonate is alkaline.
• Calcium Sulphate exists in the forms of white solids and is not soluble in water.
• Plaster of Paris and Gypsum are its hydrates.

Concept:

An array is a data structure that contains a group of elements. These elements are all of the same data type, such as an integer.

To access element from an array subscript(index) and array name is required

Explanation:

Array name: A

To access 3^rd element in an array A[2] or 2[A] is used.  Therefore Both A[2] and 2[A] represent the value 3

Important point:

A[0] represent the value 1^st element

The correct answer is Nitrification.

Key Points

• The process of conversion of ammonia into nitrate nitrogen is called nitrification.
• It is done in two steps- Nitrite formation, Nitrate formation.
• Nitrite formation- Ammonia are oxidized to nitrites by Nitrococcus, Nitrosomonas.

Additional Information

• The nitrogen cycle has four steps-
  • Nitrogen Fixation- Conversion of molecular nitrogen into the inorganic nitrogenous compound.
  • Ammonification- Conversion of the dead organic nitrogenous compound into ammonia.
  • Nitrification- Oxidation of ammonia into nitrates.
  • Denitrification- Nitrites or nitrates converts back into molecular nitrogen.

According to given information,

Whatever be the distance covered by the person, when the man stops he is facing south.

Hence, the answer is ‘South’.

Rickshaw, bus and train are the means of transport.

Mobile and radio are the means of communication, so out of the given options only letter is a mean of communication.