Question Discussion & Solution

J.K Rowling – She is a British writer.

Chetan Bhagat – He is an Indian writer.

Premchand – He was an Indian writer.

R.D Burman – He was an Indian music director.

The correct answer is Al2O3.

Key Points

•  Al2O3  reacts with acids and bases.
  • Aluminum oxide (Al2O3) is an amphoteric substance.
  • The amphoteric substance is a substance that can react with both acids and bases usually to produce salt and water.
  • Aluminium oxide therefore can react with both acids as well as bases. We will take the example of its reaction with hydrochloric acid (strong acid) and sodium hydroxide (strong base).
  • When mixed with these two compounds aluminium oxide either acts like  acid with a base and a base with an acid.

Additional Information

• Al₂O₃ + 6 HCl → 2 AlCl₃ + 3 H₂O (acts like a base)
• Al2O3 + 2 NaOH + 3 H₂O → 2 NaAl(OH)₄ (sodium aluminate) (acts like an acid)
• On reacting Al2O3 with HCl, we get Aluminium Chloride as the salt and water as a by-product.
  • Likewise, the reaction between NaOH ( Strong Base) and Al₂O₃ results in the formation of Sodium Aluminate as salt and water.

The correct answer is option 2 i.e C₄H_10.

Concept:

Hydrocarbons

• Compounds made of carbon and hydrogen atoms only are called hydrocarbons.
• Saturated hydrocarbons:
  • The hydrocarbons in which carbon atoms are singly bonded are called saturated hydrocarbons.
  • Saturated hydrocarbons are also called alkanes or paraffin.
    • The general formula of alkane– CnH2n+2.
• Unsaturated hydrocarbons:
  • The hydrocarbons in which carbon atoms are either doubly or triply bonded are called unsaturated hydrocarbons.
  • Doubly bonded (carbon atoms) hydrocarbons are called alkenes.
  • The general formula of alkene is CnH2n.

• The formula for alkane should be mentioned C_nH_2n+2

Explanation:

The correct answer is First.

• In the year 2017-18, Rajasthan was the largest millet producing state of India.

Key Points

• Rajasthan was followed by Maharashtra and Karnataka.
• The year 2023 will be observed as the International Year of Millets. 
• The Central Government declared 2018 as the year of millets. 
• Millet Mission comes under the National Food Security Mission (NFSM) which was launched in October 2007. 
• Millets include Jowar and ragi etc.

Additional Information 

• Types of Crops in India:
  • Kharif: Sown in June/July, harvested in September/October, e.g., rice, jowar, bajra, ragi, maize, cotton, and jute.
  • Rabi: Sown in October/December, harvested in April/May, e.g., wheat, barley, peas, rapeseed, mustard grains.
  • Zyad: They are raised between April/June, e.g., melons, watermelons, cucumbers, toor, leafy and other vegetables.

The pattern followed is