這份考卷有以下幾個問題
想請大家幫忙解答!!
8. Which one of the following atoms has the lowest second ionization energy?
(A)Na (B)Mg (C)Al (D)K (E)Ba
問第二游離能最低的 所以選了2A族
但為什麼答案是B不是E
Ba也是2A族 而且半徑較大 游離能應該比較小不是嗎?
14. Which one of the following transition elements has a positive Eo for
M2+(aq) +2e→ M(s)?
(A)Mn (B)Co (C)Ni (D)Cu (E)Zn
不太明白這題的答案是(D)
非選
III.A galvanic cell is constructed as follows:
Zn│0.1M ZnSO4││0.1M KMnO4,0.01M Mn2+,[H+]=1.0M│Pt
Answer the following questions using the thermodynamic data(at 25C) below
Zn(s) Zn2+(aq) Mn2+(aq) MnO4-(aq) H+(aq) H2O(l)
______________________________________________________________________________
ΔHfo(kJ*mol-1) 0 -154 -221 -541 0 -286
Sfo(J*K-1*mol-1) 42 -112 -74 191 0 70
(D)Calculate the cell potential for the constructed galvanic cell at 25度C
(E)If the cell generates a constant current of 1.0A for the first 5 minutes,
find the rate of disappearance (in M/min) at 25度C for MnO4- during this
period of time (F=96485 coulombs)
這兩題不曉得要怎麼算
用了Q=I*t=nrF
但不曉得要算什麼@@
再麻煩各位幫忙
感激不盡!!
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