To obtain 80 mol of sodium hydroxide (NaOH) from the electrolysis of an aqueous solution of NaCl, where
70% of its mass is water, what mass of this solution, in kg, should be used?
how much does 80 mol of NaCl weigh ?
Na = 23 g/mol then * 80 = 1840 grams
Cl =35.5 g/mol then * 80 = 2840 grams
sum = 4680 grams of NaCl = 30% of the mass
so
mass = 4680 grams/ 0.30 * 1 kg/1000 grams = 15.6 kg