InterviewSolution
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InterviewSolution
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a The density of 3M solution of sodium thiosulphate (Na2S0s)is1.58 g/ml.Calculate(i) amount of Na2S2O3 in % w/we (ii) mole fraction of Na2S203o (ii) molality of Na* and S2032- ions. |
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Answer» Let us consider 1.0 L solution for all the calculation. (i) Weight of 1 L solution = 1580 g Weight of Na2S2O3 = 3 × 158 = 474 g ⇒ Weight percentage of Na2S2O3 = (474/1580 )× 100 = 30%(ii) Weight of H2O in 1 L solution = 1580 – 474 = 1106 g Mole-fraction = 3/(3+ 1106/18) = 0.0465 (iii) Molality of Na+ = (3 ×2)/1106 × 1000= 5.42 m Molality of S2O_3^(2-) = (3 )/(1106 ) × 1000 = 2.71 m |
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