Carbon and Its Compounds Exemplar Problems MCQ I

Exemplar Problems MCQ I

• Carbon exists in the atmosphere in the form of
  • carbon monoxide only
  • carbon monoxide in traces and carbon dioxide
  • carbon dioxide only
  • coal
    
    Answer: (c) Carbon dioxide only
    
    Explanation: Carbon monoxide is produced from volcanoes and from oxidation of petroleum products. However, carbon monoxide is short-lived and is eventually oxidized into carbon dioxide.
• A molecule of ammonia (NH3) has
  • only single bonds
  • only double bonds
  • only triple bonds
  • two double bonds and one single bond
    
    Answer: (a) Only single bonds
    
    Explanation: Nitrogen’s valency is 3 and hence one atom of nitrogen combines with three atoms of hydrogen in a molecule of ammonia.