300 gram urea co(nh2)2 dilarutkan dalam 270 gram air. jika tekanan uap jenuh air pada suhu 800c = 700 mmhg. (ar h = 1, ar c = 12, ar n = 14, ar o = 16) a. tentukan fraksi mol larutan urea b. tentukan penurunan tekanan uap jenuh larutan. c. tentukan tekanan uap larutan.
Penjelasan:
dik : m urea = 300 g
m air = 270 g
Po = 700 mmHg
Dit :
a). X urea = ?
b). ΔP = ?
c). P larutan = ?
jb :
Mr urea = 60
Mr air = 18
– n urea :
n = m / mr
n = 300 g / 60 g/mol
n = 5 mol
– n air :
n = m / mr
n = 270 g / 18 g/mol
n = 15 mol
a). X urea = nt / nt + np
= 5 mol / 5 mol + 15 mol
= 5 mol / 20 mol
= 0.25
b). ΔP = Po * X urea
= 700 mmHg * 0.25
= 175 mmHg
c). ΔP = Po – Plarutan
Plarutan = Po – ΔP
= 700 mmHg – 175 mmHg
= 525 mmHg
semoga membantu….