Here's how to calculate the moles of sodium nitrate (NaNO₃) in 2.85 grams:

1. Find the molar mass of NaNO₃:

* Na: 22.99 g/mol

* N: 14.01 g/mol

* O: 16.00 g/mol (and there are three oxygen atoms)

Molar mass of NaNO₃ = 22.99 + 14.01 + (3 * 16.00) = 85.00 g/mol

2. Use the following formula:

Moles = Mass / Molar mass

3. Plug in the values:

Moles = 2.85 g / 85.00 g/mol

4. Calculate:

Moles = 0.0335 mol

Therefore, there are approximately 0.0335 moles of sodium nitrate in 2.85 grams.