Arrange the following in the increasing order of oxidation state of nitrogen:
A. \(NO\)
B. \(NO_2\)
C. \(N_2O_5\)
D. \(N_2O\)
E. \(N_2O_3\)
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is option 4. D < A < E < B < C.
The oxidation state (or oxidation number) of an element in a compound represents the number of electrons lost or gained by an atom of that element when forming the compound. In general:
Oxygen (O) usually has an oxidation state of -2.
Nitrogen (N) can have various oxidation states ranging from \(-3\) to \(+5\), depending on the compound.
Calculation of Oxidation States in Each Compound
A. \(NO\) (Nitric oxide)
Composition: 1 nitrogen (N) and 1 oxygen (O).
Let us assume the oxidation state of nitrogen is \(x\).
Oxygen has an oxidation state of \(-2\).
\(x + (-2) = 0 \quad \Rightarrow \quad x = +2\)
Oxidation state of nitrogen in \(NO\): +2.
B. \(NO_2\) (Nitrogen dioxide)
Composition: 1 nitrogen (N) and 2 oxygens (O).
Let us assume the oxidation state of nitrogen is \(x\).
Oxygen has an oxidation state of \(-2\).
\(x + 2(-2) = 0 \quad \Rightarrow \quad x - 4 = 0 \quad \Rightarrow \quad x = +4\)
Oxidation state of nitrogen in \(NO_2\): +4.
C. \(N_2O_5\) (Dinitrogen pentoxide)
Composition: 2 nitrogens (N) and 5 oxygens (O).
Let us assume the oxidation state of nitrogen is \(x\).
Oxygen has an oxidation state of \(-2\).
\(2x + 5(-2) = 0 \quad \Rightarrow \quad 2x - 10 = 0 \quad \Rightarrow \quad 2x = 10 \quad \Rightarrow \quad x = +5\)
Oxidation state of nitrogen in \(N_2O_5\): +5.
D. \(N_2O\) (Nitrous oxide)
Composition: 2 nitrogens (N) and 1 oxygen (O).
Let us assume the oxidation state of nitrogen is \(x\).
Oxygen has an oxidation state of \(-2\).
\(2x + (-2) = 0 \quad \Rightarrow \quad 2x - 2 = 0 \quad \Rightarrow \quad 2x = 2 \quad \Rightarrow \quad x = +1\)
Oxidation state of nitrogen in \(N_2O\): +1.
E. \(N_2O_3\) (Dinitrogen trioxide)
Composition: 2 nitrogens (N) and 3 oxygens (O).
Let us assume the oxidation state of nitrogen is \(x\).
Oxygen has an oxidation state of \(-2\).
\(2x + 3(-2) = 0 \quad \Rightarrow \quad 2x - 6 = 0 \quad \Rightarrow \quad 2x = 6 \quad \Rightarrow \quad x = +3\)
Oxidation state of nitrogen in \(N_2O_3\): +3
Here are the oxidation states of nitrogen in each compound:
\(N_2O\): +1
\(NO\): +2
\(N_2O_3\): +3
\(NO_2\): +4
\(N_2O_5\): +5
Now, we arrange the compounds in order of increasing oxidation states of nitrogen:
The lowest oxidation state is +1 in \(N_2O\).
The next is +2 in \(NO\).
Then, +3 in \(N_2O_3\).
Followed by +4 in \(NO_2\).
Finally, the highest oxidation state is +5 in \(N_2O_5\).
Thus, the increasing order of oxidation states is:
\(\textbf{D (N}_2\textbf{O)} < \textbf{A (NO)} < \textbf{E (N}_2\textbf{O}_3\textbf{)} < \textbf{B (NO}_2\textbf{)} < \textbf{C (N}_2\textbf{O}_5\textbf{)} \)
Conclusion
The correct answer is option 4: D < A < E < B < C.
This sequence correctly represents the increasing order of oxidation states of nitrogen in the given compounds.