The keyword silver nitrate formula refers to the chemical formula of the ionic compound silver nitrate. The correct formula is AgNO3, obtained by combining the silver cation and the nitrate anion in the smallest whole-number ratio that produces overall electrical neutrality.
1) Identify the ions that make silver nitrate
Silver nitrate is composed of a metal cation (silver) and a polyatomic anion (nitrate). Their common ionic forms in general chemistry are:
| Species | Ion | Charge | Reason this charge is used |
|---|---|---|---|
| Silver ion | \(\mathrm{Ag^+}\) | \(+1\) | Silver commonly forms silver(I) in ionic compounds. |
| Nitrate ion | \(\mathrm{NO_3^-}\) | \(-1\) | Nitrate is a polyatomic ion with a fixed \(-1\) charge. |
2) Apply charge balance to get the formula
An ionic compound formula must be electrically neutral. Therefore, the total positive charge contributed by cations must equal the total negative charge contributed by anions.
Charge-balance step.
The charges are \(+1\) for \(\mathrm{Ag^+}\) and \(-1\) for \(\mathrm{NO_3^-}\). The smallest whole-number combination that sums to zero is one of each: \[ (+1) + (-1) = 0. \] Therefore, the formula unit is \[ \mathrm{AgNO_3}. \]
3) Visualization: formula unit and 1:1 ion ratio
4) Common checks and extensions
- Parentheses rule: Parentheses are used only when more than one polyatomic ion is needed (for example, \(\mathrm{Ca(NO_3)_2}\)). For silver nitrate, only one nitrate is required, so \(\mathrm{AgNO_3}\) uses no parentheses.
- Name–formula consistency: “Silver nitrate” implies silver(I) paired with nitrate; the corresponding formula is \(\mathrm{AgNO_3}\).
- Optional molar mass (often asked with formulas): using atomic masses \(M(\mathrm{Ag})\approx 107.87\), \(M(\mathrm{N})\approx 14.01\), \(M(\mathrm{O})\approx 16.00\), \[ M(\mathrm{AgNO_3}) \approx 107.87 + 14.01 + 3\times 16.00 = 169.88\ \text{g/mol}. \]
The silver nitrate formula is AgNO3, obtained by combining \(\mathrm{Ag^+}\) and \(\mathrm{NO_3^-}\) in the smallest whole-number ratio that yields a neutral ionic compound.