## Chemistry (4th Edition)

1. Find the number of moles: $Concentration(M) = \frac{n(mol)}{V(L)}$ $0.707 = \frac{n(mol)}{0.25}$ $0.707 * 0.25 = n(mol)$ $0.177 moles = n(mol)$ 2. Determine the molar mass of this compound ($NaNO_3$): 22.99* 1 + 14.01* 1 + 16* 3 = 85g/mol 3. Calculate the mass $mm(g/mol) = \frac{mass(g)}{n(mol)}$ $mm(g/mol) * n(mol) = mass(g)$ $85 * 0.177 = mass(g)$ $15 = mass(g)$ So, we just need to add this mass of solid sodium nitrate in water to reach 250 mL of solution.