Using the following data, Compound Melting Point (C) ?Hfus (kJ/mol) Boiling Poin
ID: 956058 • Letter: U
Question
Using the following data,
Compound
Melting Point (C)
?Hfus (kJ/mol)
Boiling Point (C)
?Hvap (kJ/mol)
HF
-83.11
4.577
19.54
25.18
HCl
-114.3
1.991
-84.9
17.53
HBr
-86.96
2.406
-67
19.27
HI
-50.91
2.871
-35.38
21.16
calculate ?Sfus and ?Svap for HI. Both in units of J/(K x Mol)
Determine the entropy change when 6.80 mol of HI(l) freezes at atmospheric pressure in J/K.
Compound
Melting Point (C)
?Hfus (kJ/mol)
Boiling Point (C)
?Hvap (kJ/mol)
HF
-83.11
4.577
19.54
25.18
HCl
-114.3
1.991
-84.9
17.53
HBr
-86.96
2.406
-67
19.27
HI
-50.91
2.871
-35.38
21.16
Explanation / Answer
dSfus = dHfus/Tfus = 2.871/(-50.91+273) = 0.01292 kJ/molK = 12.92 J/moK
dSvap= dHvap/Tvap = 21.16/(-35.38+273) = 0.089049 kJ/molK = 89.05 J/molK
then
for n = 6.8 mol
dS = 6.8*-(12.92) =87.856 J/K
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.