General Chemistry 2 Final-term Exam Fall, 2014 (1/2)

감독자인
계열/학부/학과: 학번: 고유번호: 성명:
수업요일 및 담당교수명: ( , )요일 ( )교수 자필서명:

H He <주의 사항>
Li Be B C N O F Ne 1. 답은 지정된 자리에 반드시 영문(English)으로 기입할 것.
Na Mg Al Si P S Cl Ar 2. 시험 시간은 60분임. 400점 만점 (full score = 400 pt).
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 3. 문제지는 1장(2면)임. 연습지 및 영한사전 사용 불가.
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 4. 계산문제는 풀이과정을 반드시 밝힐 것.(단위, 유효숫자에 유의)
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 5. 계산기 사용 무방하나 빌려 쓰지는 못함.
Fr Ra Ac 6. gas constant R = 8.314 J/mol⦁K = 0.0821 L⦁atm/mol⦁K

1. Write ‘T’ for true statement or ‘F’ for false statement in ( ).

–
[5 pt for right answer, 3 pt for wrong, and 0 pt for no answer]
(B ) Which of the following elements is not found in DNA?
(A) N (B) S (C) H (D) O (E) P
(E ) For a spontaneous exothermic process, which of the following
(T ) Many weak acids react with metal ions to form insoluble
must be true?
compounds.
(A) ∆G must be positive. (B) ∆S must be positive.
(F ) If you have Cr(OH)3 dissolved in water, adding NaOH will
(C) ∆S must be negative. (D) Two of the above must be true.
increase the solubility.
(E) None of the above (A-C) must be true.
(F ) If the ∆S is negative and the ∆H is positive, the reaction will
(C ) What is voltage of a cell made of two nickel electrodes with
be spontaneous at low temperatures.
nickle(II) ion concentrations of 0.50 M and 1.0☓10-4 M in the
(T ) The ∆Ssys is positive and the ∆Ssurr is negative for the melting 2+ – o
two half-cells. Ni + 2e → Ni (E = –0.23V)
of ice.
(A) –0.23V (B) –0.42V (C) –0.11V (D) 0.16V (E) 0.25V
(T ) Anode is where the oxidation occurs and negative in galvanic
(E ) How many hydrogen ions (H+) are involved after balancing
cells.
the following oxidation-reduction reaction in acidic solution.
(T ) The line notation of Mg(s)|Mg2+(aq)||Al3+(aq)|Al(s) means that Br–(aq) + MnO4–(aq) → 2+
Br2(l) + Mn (aq)
magnesium (Mg) will be oxidized and aluminum (Al) be (A) 2 (B) 3 (C) 5 (D) 7 (E) 16
reduced. (A ) What is not suitable for corrosion protection?
(T ) The protein myoglobin stores oxygen in muscle cells. (A) Anodic protection (B) Metal coating (C) Alloying
(T ) The isomers of non-superimposable mirror images are called (D) Galvanizing (E) Preventing direct oxygen exposure
enantiomers. (E ) What is the coordination number of cobalt in [Co(en)2Cl2]Cl?
(F ) A monomer is a high-molecular-weight chain of small [en = ethylenediamine]
molecules. (A) four (B) five (C) three (D) eight (E) six
(F ) Benzene readily undergoes addition reactions but not (D ) Which of the following materials is added to the blast
furnace to produce slag?
substitution reactions.
(A) sulfur (B) carbon (C) silicon (D) limestone (E) N2
(C ) Which ligand formula is incorrectly matched with its name as
2. Choose the correct answer and write it in ( ). [8 pt each]
a ligand?
(A) NH3 - ammine (B) H2O - aqua (C) NO - nitrito
(C ) Which of the following leads to the formation of a – 2–
(D) OH - hydroxo (E) C2O4 - oxalato
precipitate?
(D ) Which one of the following is a secondary amine?
(A) Q = Ksp (B) Q < Ksp (C) Q > Ksp (D) Q = 1 (E) K = 1
(A) CH3NH2 (B) (CH3)3N (C) HOCH2CH2NH2
(D ) Which of the following salts shows the lowest solubility in
–49 –72 (D) (CH3)2NH (E) None of the above
water? (Ksp: Ag2S = 1.6 ´ 10 ; Bi2S3 = 1.0 ´ 10 ; HgS = 1.6 ´
(A ) is the best known polyamide.
10–54; Mg(OH)2 = 8.9 ´ 10–12; MnS = 2.3 ´ 10–13)
(A) nylon (B) Teflon (C) PET [poly(ethylene terephthalate)]
(A) Bi2S3 (B) Ag2S (C) MnS (D) HgS (E) Mg(OH)2
(D) polyethylene (E) rubber
(A ) In which of the following reactions do you expect to have
(C ) Which of the following hydrocarbons can exist as cis-trans
the largest increase in entropy?
isomers?
(A) I2(s) → I2(g) (B) 2IF(g) → I2(g) + F2(g)
(A) 2-methyl-2-butene (B) 1-butene (C) 2-butene
(C) Mn(s) + O2(g) → MnO2(s) (D) Hg(l) + S(s) → HgS(s)
(D) 2-methyl-1-butene (E) methylpropene
(E) CuSO4(s) + 5H2O(l) → CuSO4·5H2O(s)

<Do not write below>

1 2 3 4 5 6 7 8 9 10 11 12 13 Total
50 112 15 20 15 20 20 15 30 40 30 20 13 400
 General Chemistry 2 Final-term Exam Fall, 2014 (2/2)

3. A 1.0 L solution contains 0.010 M of Mn(NO3)2. NaOH(s) is 8. Write the name of the ligands or chemical formula of the
added until the pH of the solution is 8.50. Is this concentration followings. [5 pt each]
2–
of NaOH enough to have Mn(OH)2(s)? (a) O ( oxo ) (b) CO ( carbonyl )
Ksp for Mn(OH)2 = 2.0 ´ 10–12. [15 pt] (c) Potassium hexachlorochromate(III) ( K3[Cr(Cl)6] )

* Standard reduction potential at 25oC (9-10).

O2(g) + 4H+(aq) + 4e– → 2H2O(l) (Eo = +1.23V)
2H2O(l) + 2e–
→ H2(g) + 2OH-(aq) (Eo = –0.83V)
(Check the final value.) +
Na + e
–
→ o
Na (E = –2.71V) Cl2 + e
–
→ - o
2Cl (E = +1.36V)
2+
Zn + 2e →
– o
Zn (E = –0.76V) Ag + e
+ –
→ o
Ag (E = +0.80V)

4. How many moles of solid ammonium chloride, NH4Cl, must

3+
Fe + e
–
→ 2+ o
Fe (E = +0.77V) Cu + 2e
2+ –
→ o
Cu (E = +0.34V)
F = 96500 C/mol, R = 8.314 J/mol⦁K, ln = 2.303 log
be used to prevent precipitation of Mg(OH)2 in one litre of
solution that is 0.15 M in aqueous ammonia and 0.025 M in 9. Write the main products formed at the two electrodes in the
–11
magnesium nitrate, Mg(NO3)2? Ksp for Mg(OH)2 = 1.5 ´ 10 ,
–5 electrolysis using the following electrolytes. All the electrode is Pt,
Kb for NH3 = 1.8 ´ 10 . [20 pt]
if not mentioned. [5 pt each]
electrolyte(phase)/electrode anode(phase) cathode(phase)
Molten NaCl(s) Cl2 ( g ) Na (s)
NaCl(aq) Cl2 ( g ) H2 ( g )
Na2SO4(aq) O2 ( g ) H2 ( g )
2+
CuSO4(aq) / Cu anode / Pt cathode Cu ( aq ) Cu ( s )

10. Calculate the values at STP. [20 pt each]

│
(1) Calculate K for Zn(s) Zn2+(aq, 1M) ║Ag (aq, 1M)│Ag(s).
+

E0=+0.80-(-0.76)=1.56 V n = 2
o o
5. Given the following data, calculate the normal boiling point for -nFE =-2☓96500☓1.56= -301 kJ/mol = -2.303 RT log K (= ΔG )
formic acid (HCOOH). [15 pt] ∴ o
log K = nFE /2.303RT = 301,000/(2.303☓8.314☓298)=52.753
DHf°(kJ/mol) S°(J/mol K) K= 5.66☓1052 (K = 1.0 x 1052 to 9.9 x 1053 is OK.)
HCOOH(l) –410.0 130.0
HCOOH(g) –363 251.1 (2) Calculate voltage of a whole cell made of Fe2+(aq, 0.0010
M)/Fe3+(aq, 1.0 M) half cell and Cu2+(aq, 0.10 M)/Cu(s) half cell.
→
2Fe3+(aq)+Cu(s) 2Fe2+(aq)+Cu2+(aq) E0=0.771-0.337=+0.434 V
E=E0-(0.0591/2)log{[Fe2+]2[Cu2+]/[Fe3+]2}
= +0.44-0.0591/2☓log[0.0012☓0.1/12]=+0.44 + 0.207
= +0.65 V
6. Water gas, a commercial fuel, is made by the reaction of hot
coke carbon with steam. When equilibrium is established at
11. Draw the final products in [ ]. [15 pt each]
844°C the concentrations of CO, H2, and H2O are 4.00 ´ 10–2,
–2 –2
4.00 ´ 10 , and 1.00 ´ 10 mole/liter, respectively. Calculate the
value of DG° for this reaction at 844°C.
C(s) + H2O(g) → CO(g) + H2(g) [20 pt]
(1) CH3CO2H

(2)

12. Write the structures for all possible isomers of C6H4Cl2 that
contains a phenyl ring. [20 pt]

7. Fill up the electron configuration (in t2g and eg) for the
following complexes containing for Co3+ and Co2+ using crystal
field model. Indicate spin and magnetic properties. [10 pt each]
t2g eg
⇅
(a) [Co(NH3)6]3+ _ _ _⇅_ _⇅_ __ __ 13. Identify all chiral carbon atom(s) in the following structure
with an asterisk(*). [13 pt]
( low )-spin; ( dia )-magnetic

(b) [CoCl6]4– _⇅_ _⇅_ _↑_ _↑_ _↑_

( high )-spin; ( para )-magnetic

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