Discussion
In the following reaction, the change in oxidation state of Magnesium is
\(\mathrm{3Mg_{(s)} + N_{2(g)} \xrightarrow{\Delta} Mg_{3}N_{2(s)}}\)
Answer: A
Magnesium changes from 0 to +2.
Free magnesium metal, \(\mathrm{Mg_{(s)}}\), is an element in its standard state, so its oxidation state is 0. In magnesium nitride, \(\mathrm{Mg_{3}N_{2}}\), nitrogen is the more electronegative element and takes -3:
\[ \begin{aligned} 3x + 2(-3) &= 0 \\ x &= +2 \end{aligned} \]
So each magnesium atom loses two electrons and is oxidised, while nitrogen goes from 0 to -3 and is reduced. +3, +4 and +6 are not oxidation states of magnesium, a group 2 metal that only ever shows +2 in compounds, and a negative value would mean magnesium had gained electrons.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development