what mass in grams of sodium nitrate is needed to make 85.o ml of a 0.2500 m solution

To determine the mass of sodium nitrate needed to make a solution, you need to use the formula:

Mass = Volume x Concentration x Molar mass

Step 1: Convert the volume from milliliters (ml) to liters (L):
85.0 ml = 85.0/1000 L = 0.085 L

Step 2: Determine the molar mass of sodium nitrate (NaNO3):
Na: 1 x 22.99 g/mol = 22.99 g/mol
N: 1 x 14.01 g/mol = 14.01 g/mol
O: 3 x 16.00 g/mol = 48.00 g/mol

Total molar mass of NaNO3 = 22.99 + 14.01 + 48.00 = 84.00 g/mol

Step 3: Calculate the mass of sodium nitrate:
Mass = Volume x Concentration x Molar mass

Mass = 0.085 L x 0.2500 mol/L x 84.00 g/mol

Mass = 0.21225 g

Therefore, you would need approximately 0.21225 grams of sodium nitrate to make a 0.2500 M solution with a volume of 85.0 ml.