A black compound of manganese reacts with a halogen acid
to give greenish yellow gas. When excess of this gas reacts
with NH₃ an unstable trihalide is formed. In this process the
oxidation state of nitrogen changes
from ........... .
(a) – 3 to + 3 (b) – 3 to 0
(c) – 3 to + 5 (d) 0 to – 3
Answers
The oxidation state of nitrogen changes from -3 to +3.The oxidation state of nitrogen changes from -3 to +3.
• A compound of manganese which is black in color is manganese dioxide (MnO₂).
• A halo acid means an acid of halogen, having the general formula HX, where X is a halogen.
• A greenish-yellow gas is evolved, means chlorine gas is evolved on reaction as it is characterized by a greenish-yellow colour.
• This suggests that the halo acid used as a reactant is hydrochloric acid (HCl).
• The reaction can be represented as follows :
MnO₂ + 4HCl → MnCl₂ + Cl₂ + 2H₂O
• The reaction between NH₃ and Cl₂ proceeds as follows :
2NH₃ + 6Cl₂ → 2NCl₃ + 6HCl
The unstable trihalide formed is nitrogen tricholide (NCl₃).
• Oxidation state of nitrogen in NH₃ can be calculated as :
x + 3 = 0
=> x = -3
Oxidation state of nitrogen in NCl₃ can be calculated :
x - 3 = 0
=> x = 3
• Therefore, the change in oxidation number is -3 to +3.
Hello Friend..!!
The answer of your question is..!!
Option.A
Thank you