Question #d9ce7

1 Answer

Answer:

#T_2 = "291 K" = 17.8^@ "C"#

Explanation:

Use the ‘Clausius - Clapeyron Equation’ with

#VP_1 = "760 mm Hg"# @ #T_1 = "373 K"#

#VP_2 = "19 mm Hg"# @ #T_2 = ?#

#R = "8.314 J/mol"cdot"K" = "0.008314 kJ/mol"cdot"K"#

#∆H_(vap) = "40.67 kJ/mol"#.

And so:

#ln((VP_2)/(VP_1)) = ((∆H_(vap))/R)[1/T_1 – 1/T_2]#

#ln(19/760) = (40.67/0.008314)[1/373 – 1/(T_2)]#

#ln(0.025) = (4865)[0.0027 – 1/T_2] = 13.04 – 4865/T_2#

#=> -3.69 = 13.04 - 4865/T_2 #

Rearrange to solve for #T_2#.

#T_2 = [(4865)/(13.04 + 3.69)]"K"#

#= (4865/16.73)# #"K"# #=# #"291 K"#

Or in #""^@ "C"#,

#T_2 = (291 - 273)""^@"C"#

#= 17.8^@ "C"#