To determine the oxidation number of nitrogen (N) in the compound [tex]\(\text{Ca(NO}_3\text{)}_2\)[/tex], let's follow a systematic approach:
1. Identify the overall charge of the compound:
- Calcium nitrate, [tex]\(\text{Ca(NO}_3\text{)}_2\)[/tex], is a neutral compound, so the sum of the oxidation numbers of all atoms in the compound must equal zero.
2. Determine the oxidation numbers of known elements:
- Calcium (Ca) is an alkaline earth metal and typically has an oxidation number of +2.
- Oxygen (O) typically has an oxidation number of -2.
3. Analyze the structure of the compound:
- The formula [tex]\(\text{Ca(NO}_3\text{)}_2\)[/tex] indicates that there are two nitrate ions ([tex]\(\text{NO}_3^-\)[/tex]) associated with one calcium ion (Ca[tex]\(^2+\)[/tex]).
- The nitrate ion, [tex]\(\text{NO}_3^-\)[/tex], has an overall charge of -1.
4. Sum of oxidation numbers in the nitrate ion ([tex]\(\text{NO}_3^-\)[/tex]):
- Let’s assign the oxidation number of nitrogen (N) as [tex]\(x\)[/tex].
- In one nitrate ion ([tex]\(\text{NO}_3^-\)[/tex]), there are three oxygen atoms, each contributing an oxidation number of -2.
- Therefore, the total contribution of the oxygen atoms in [tex]\(\text{NO}_3^-\)[/tex] is [tex]\(3 \times (-2) = -6\)[/tex].
5. Set up the equation for the nitrate ion:
- The sum of oxidation numbers in the [tex]\(\text{NO}_3^-\)[/tex] ion must equal its charge, which is -1.
- So, we set up the equation: [tex]\[ x + 3(-2) = -1 \][/tex]
- Simplifying the equation: [tex]\[ x - 6 = -1 \][/tex]
- Solving for [tex]\(x\)[/tex]: [tex]\[ x = -1 + 6 \][/tex]
- [tex]\[ x = +5 \][/tex]
6. Conclusion:
- The oxidation number of nitrogen (N) in [tex]\(\text{Ca(NO}_3\text{)}_2\)[/tex] is +5.
So, the oxidation number of N in [tex]\(\text{Ca(NO}_3\text{)}_2\)[/tex] is [tex]\(\boxed{5}\)[/tex].
