1. Find the molar mass of nitrate ions:
* Nitrogen (N) has a molar mass of 14.01 g/mol
* Oxygen (O) has a molar mass of 16.00 g/mol
* Nitrate (NO₃⁻) has one nitrogen and three oxygen atoms: (14.01 g/mol) + (3 * 16.00 g/mol) = 62.01 g/mol
2. Use the molar mass to convert moles to grams:
* 0.25 moles NO₃⁻ * (62.01 g NO₃⁻ / 1 mole NO₃⁻) = 15.5 g NO₃⁻
Therefore, the mass of 0.25 moles of nitrate ions is 15.5 grams.
