Question

10 points Save As. What is the freezing point of aqueous solution containing 10 grams of disodium phosphate (Na2HPO4, MW-142) dissolved in 500 ml of water? disodium phosphate is a uni-divalent electrolyte DO NOT TYPE UNITS IN YOUR ANSWER

Answer 1

If we assume 100% dissociation of Na HPO 4 it will dissociate into three ions - NqHPO4 = 2 watt HPO, so its vant Hoff factor i is 3. we know density of water is 1.0 g/mL .. Molality of solution = Moles Mars of sowent in kg 109/1429/mo 500 mLx2g/mL x Kg sila .. slovog - -.0:14 g mol/kg . vant Hoff factor is. 3, so actual observed molality - Bro.igm = 0.62m. We know of Kigom (where, ATt - depression in 3 freezing point If a molal depression constant] ..hops Ki for water i = 1.86°c/m. . = 7086 °C/m X 0:42. m est in 0.078.00 i3 , i n Freezing point of pure water 2.0°C.... 3 freezing point of solition = -0.78°C solution 3. 0.7& c.