posted by Dem on .
If a procedure calls for 2mL of a concentrated nitric acid, what are the mass and moles of the HNO3 actually used in the reaction?
How concentrated is the "concentrated" HNO3?
If you are talking about commercial grade conc HNO3, it has a density of about 1.4 g/mL and it is about 68% by weight HNO3. You need to confirm these values from your text or notes and use those numbers instead of these estimates.
mass soln = 1.40g/mL x 2 mL = ?
mass HNO3 = ?g mass soln x 0.68 = ? g HNO3
mols HNO3 = grams HNO3/molar mass HNO3.