증기압내림. 82.4 g of urea in 212 mL of water at 35℃

증기압내림. 82.4 g of urea in 212 mL of water at 35℃

 

 

35℃에서 물(18.02 g/mol) 212 mL에

요소(60.06 g/mol) 82.4 g을 녹여 만든

용액의 증기압을 계산하시오.

35℃에서 물의 증기압은 42.18 mmHg.

 

 

Calculate the vapor pressure of a solution

made by dissolving 82.4 g of urea (molar mass = 60.06 g/mol)

in 212 mL of water at 35°C. What is the vapor-pressure lowering?

 

---------------------------------------------------

▶ 참고: 88.2 g of urea in 303 mL of water at 35℃

[ https://ywpop.tistory.com/14794 ]

---------------------------------------------------

 

35℃ 물의 밀도 = 0.994 g/mL

212 mL × (0.994 g/mL) = 210.728 g H2O

 

 

 

210.728 g × (1 mol / 18.02 g) = 11.69 mol H2O

 

 

 

82.4 g × (1 mol / 60.06 g) = 1.372 mol urea

 

 

 

n_tot = 11.69 + 1.372 = 13.06 mol

 

 

 

X_H2O = 11.69 / 13.06 = 0.8951

( 참고: 몰분율 https://ywpop.tistory.com/2659 )

 

 

 

P_용매 = X_용매 × P°_용매

( 참고 https://ywpop.tistory.com/2646 )

 

= 0.8951 × 42.18 mmHg

= 37.76 mmHg

 

 

 

답: 37.8 mmHg

 

 

 

 

[키워드] 35℃ water 212 mL urea 82.4 g 42.18 mmHg, 35℃ water 212 mL 82.4 g vapor pressure 42.18 mmHg

 

[①22/06/10]