## Chemistry (7th Edition)

(a) 1. Find the number of moles: $Concentration(M) = \frac{n(mol)}{V(L)}$ $1.25 = \frac{n(mol)}{0.5}$ $1.25 * 0.500 = n(mol)$ $0.625 moles = n(mol)$ 2. Determine the molar mass of this compound (NaOH): 22.99* 1 + 16* 1 + 1.008* 1 = 39.998g/mol 3. Calculate the mass $mm(g/mol) = \frac{mass(g)}{n(mol)}$ $mm(g/mol) * n(mol) = mass(g)$ $39.998 * 0.625 = mass(g)$ $25.0 = mass(g)$ (b) 1. Find the number of moles: $Concentration(M) = \frac{n(mol)}{V(L)}$ $0.250 = \frac{n(mol)}{1.5}$ $0.250 * 1.50 = n(mol)$ $0.375 moles = n(mol)$ 2. Determine the molar mass of this compound ($C_6H_{12}O_6$): 12.01* 6 + 1.008* 12 + 16* 6 = 180.156g/mol 3. Calculate the mass $mm(g/mol) = \frac{mass(g)}{n(mol)}$ $mm(g/mol) * n(mol) = mass(g)$ $180.156 * 0.375 = mass(g)$ $67.6 = mass(g)$