Reserpine 1.00 g camphor 25.0 g 2.63℃

Reserpine is a natural product isolated from the roots of the shrub Rauwolfia serpenlina. It was first synthesized in 1956 by Nobel Prize winner R. B. Woodward. It is used as a tranquilizer and sedative.

When 1.00 g reserpine is dissolved in 25.0 g camphor,

the freezing-point depression is 2.63℃

(Kr for camphor is 40. ℃•kg/mol).

Calculate the molality of the solution

and the molar mass of reserpine.

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어는점내림

ΔTf = Kf × m 이므로,

( 참고 https://ywpop.tistory.com/1920 )

m = ΔTf / Kf

= 2.63 / 40.

= 0.06575 mol/kg

---> molality of the solution

몰랄농도 = 용질 mol수 / 용매 kg수 이므로,

( 참고 https://ywpop.tistory.com/2667 )

용질 mol수 = 몰랄농도 × 용매 kg수

= (0.06575 mol/kg) × (25.0/1000 kg)

= 0.00164375 mol reserpine

몰질량, M = W / n 이므로,

( 참고 https://ywpop.tistory.com/7738 )

= 1.00 g / 0.00164375 mol

= 608.4 g/mol

---> molar mass of reserpine

100.0 g water 17.5 g compound -1.8℃

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Reserpine 1.00 g camphor 25.0 g 2.63℃