The Formula Of Sodium Nitrate Is NOT Na2NO3. Explain Why It Is Not Correct And Give The Correct Formula.
The Correct Answer and Explanation is :
The formula of sodium nitrate is not Na₂NO₃ because it does not accurately reflect the chemical bonding and stoichiometry of sodium nitrate. The correct formula for sodium nitrate is NaNO₃.
Explanation:
Sodium nitrate is composed of sodium ions (Na⁺) and nitrate ions (NO₃⁻). The formula Na₂NO₃ suggests there are two sodium ions for each nitrate ion, but this does not match the charge balance required in the compound. Here’s why:
- Ion Charges:
- Sodium (Na) is an alkali metal in Group 1 of the periodic table and forms a cation with a charge of +1 (Na⁺).
- Nitrate (NO₃) is a polyatomic ion with a charge of -1 (NO₃⁻). This is a common ion formed by nitrogen and oxygen, where nitrogen has a +5 oxidation state, and the three oxygens carry a combined -3 charge.
- Charge Balance:
- In ionic compounds, the total positive charge must balance the total negative charge. Since the sodium ion has a charge of +1 and the nitrate ion has a charge of -1, one sodium ion (Na⁺) combines with one nitrate ion (NO₃⁻) to form a neutral compound.
- Therefore, the correct formula reflects a 1:1 ratio of Na⁺ to NO₃⁻ ions, giving NaNO₃ as the correct chemical formula.
- Why Na₂NO₃ is incorrect:
- If we were to use Na₂NO₃, there would be two sodium ions, which would give a total positive charge of +2. However, the nitrate ion has only a -1 charge, meaning the compound would not be neutral, which is essential for stable compounds.
- Therefore, the charge balance would be incorrect with Na₂NO₃.
Conclusion:
The correct formula for sodium nitrate is NaNO₃, ensuring that the ionic charges balance and the compound is electrically neutral.