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.