Breckenridge 520. torr water ΔH_vap = 40.7 kJ/mol boiling point

Breckenridge 520. torr water ΔH_vap = 40.7 kJ/mol boiling point

 

 

In Breckenridge, Colorado, the typical atmospheric pressure is 520. torr.

What is the boiling point of water (ΔH_vap = 40.7 kJ/mol) in Breckenridge?

 

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> P1 = 760. torr, T1 = 273+100 = 373 K

> P2 = 520. torr, T2 = ? K

 

 

 

클라우지우스-클라페이롱 식. Clausius-Clapeyron relation

ln(P1/P2) = ΔH_vap/R (1/T2 – 1/T1)

( 참고 https://ywpop.tistory.com/3133 )

 

 

 

ln(760. / 520.) = (40700 / 8.314) (1/T2 – 1/373)

( 주의: 8.314 J/mol•K 이므로, ΔH_vap = 40700 J/mol )

 

1/T2 – 1/373 = ln(760. / 520.) / (40700 / 8.314)

 

1/T2 = (ln(760. / 520.) / (40700 / 8.314)) + 1/373

 

T2 = 1 / [ (ln(760. / 520.) / (40700 / 8.314)) + 1/373 ]

= 363 K

 

363 – 273 = 90℃

 

 

 

답: 90.℃

( 참고: 교재 답은 362 K or 89℃로 나옴. )

 

 

 

 

T2 = 1 / [ (ln(760. / 520.) / (40700 / 8.3145)) + 1/373 ] = 362.52

362.52 – 273 = 89.52

 

T2 = 1 / [ (ln(760. / 520.) / (40700 / 8.3145)) + 1/373.15 ] = 362.66

362.66 – 273.15 = 89.51