Question

Sodium and potassium in a sample weighing 0.9250 g are converted into NaCl (58.443 g mol-1) and KCl (74.551 g mol-1) salts. The chloride mixture weighs 0.6065 g. The chlorides are then converted into Na2SO4 (142.043 g mol-1) and K2SO4 (174.260 g mol-1), the mixture weighing 0.7190 g. Calculate the percentages of Na2O (61.979 g mol-1) and K2O (94.196 g mol-1) in the original sample.

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Answer 1

let mass of Nazo in sample = xgn and that of ko ay gm. Number of moles of sodium = 2xx @1.979 moles of potassium a 2x4 94.196 Number of moles of wall a 2x Number of moles of ku= 61.979 inas 24 94.196 mass of chlorides= 0.6065g = 2 x 58443 + 2y x74.551 94,196 - 61.979 94017 1,886x + 1.5829 y = 0.6065 ---0 Number of moles of Nasof = 2 x 2 1 1 29 number of moles of Koza 1x 2 mass of sulphates = 0.7190= 2 x 142.043+ qu.19*174.260 y & 2.2918x + 1850y = 0.7190 ---- solving equation 0 4 0 for a and y x= 0.1161158 g = 0.24481 g 7. of Nazo in original sample= 0.116115 x 100 = 12.55%. (Anower) 0.9250 t. of 190 in original sample= 0.2448), x 100 = 26.474. (Answer)