Mata Kuliah Paling Sulit

Ditulis 17 Januari 2008

Physical Chemistry. Mungkin bagi seluruh mahasiswa jurusan kimia akan menemukannya. Ada yang bilang mudah dan ada yang bilang sulit. Bagiku, mata kuliah ini adalah mata kuliah yang paling sulit. Bayangkan ini kali ketiga aku mengambil mata kuliah ini, dan sampai akhir ujian siang tadi, aku gak yakin nilaiku beranjak dari C-

Ini bocoran soal hari ini :

Physical Chemistry Examination No. 2, 17 Januari 2008

1. State precisely the meaning of each of the following terms :
(a) Chemical potential, phase transition, normal and standard melting point, and critical temperature
(b) First and second order transition phase, capillary rise, and partial molar volume.

2. The molar volume of a certain solid is 161.0 cm3 mole-1 at 1,00 atm and 250,75 K, its melting temperature. The molar volume of the liquid at this temperature and pressure is 163.3 cm3 mole-1. At 100 atm the melting temperature change to 351.26 K. Calculate the molar enthalpy and entropy of fusion of the solid?

3. (a) at 30 C (303 K), the surface tension of ethanol in contact with its vapor is 0,02189 Nm-1 and density is 0.780 gcm-3. How far up a tube of internal diameters 0.20 mm will it rise? What pressure is needed to push the meniscus back level with the surrounding liquid?
(b) Calculate the Gibbs energy, entropy, and enthalpy of mixing when 1.00 mole C6H14 is mixed with 1.00 mole C7H16 at 298 K; treat the solution as ideal.
(c) For a pure substance, what is chemical potential µ ?

4. (a) Write down differential equations for the second law, reversible case !
(b) Write down the equation defining the Helmholtz energy A in term of U.
(c) Differentiate this equation and combine it with the fundamental equation to obtain a new fundamental equation in terms of dA.

5. (a) Calculate the change in entropy when 25 kJ of energy is transferred reversibly and isothermally as heat to a large block of iron at : (i) 273 K (ii) 373 K (iii) 573 K.
(b) Calculate the change in chemical potential of a perfect gas that is compress isothermally from 1.8 atm to 2.95 atm at 50 C (327 K).

Total scores : 125
= Good Luck =
(Book : Atkins P. W, Physical Chemistry, Seventh Edition, Oxford University Press)

Itulah soalnya. Aku hanya bisa menyelesaikan empat soal. Soal 1 dan 5 mungkin betul. Tapi aku tidak yakin dengan jawabanku untuk soal 2 dan 3. Untuk soal 4, aku tidak punya gambaran sama sekali. Part 4 di lembar jawabanku hanya berisi coret-coretan tidak menentu. Dengan score 50, berarti aku hanya mampu meraih nilai D. Kalo dosennya (Prof. Dr. Emriadi, MS) mau berbaik hati ngasih nilai upah menulis, mungkin score ku diatas 50 dikit, dan itu baru C-. Gimana nih. Masa di transkrip nilaiku saat wisuda nanti ada nilai C- nya, karena gak mungkin lagi diulang. Ini semester terakhirku. Help me Allah. Astaghfirullahal’adzim.