Question

The normal boiling point of methanol is 64.7°C and the molar enthalpy of vaporization if 71.8 kJ/mol. The value of DS when 2.15 mol of CH₃OH(1) vaporizes at 64.7°C is __________J/K.

	A.	0.457
	B.	2.39
	C.	5.21 x 107
	D.	457
	E.	2.39 x 103

Answer 1

We know that :- (values already mentioned in problem statement)

...(0) // 0 degree cemtigrade is 273.15 degree Kelvin (value given in problem statement)

...(1)// molar enthalpy of vaporization

...(2)// moles of methanol

Also change in enthaply is given by :-

...(3)

Now using (0), (1), (2) and (3), we have :-

...(4)

Therefore correct option is (D.) 457