作者Highhuman (Ryan)
看板TransBioChem
標題[問題] 一些問題
時間Fri Jul 6 15:14:24 2012
以下這幾題，是我目前仍然不太會算的題目:
1.A gas sample containing of CO2 and N2 in 1:2 molar ratio has a volume of
。
350ml at 40 C with a CO2 partial pressure of 560 torr. What is the
volume of the mixed gases under STP condition ?
。
2.The decomposition of dimethyl ether , (CH3)2O , at510 C is a first-order
process wuth a rate constant of 6.8*10^-4 s^-1.
(CH3)2O (g) -->CH4 (g) + H2 (g) + CO(g)
If the initial pressure of (CH3)2O is 135 torr , how long will it take
when the pressure of (CH3)2O drops to 51 torr ?
(A)17.9 s (B)1020 s (C)1430 s (D)1.23*10^5 s
3.Consider the equilibrium :N2O4 (g) <---> 2NO2 (g)
del H = 58.0 KJ , which of the following will shift the equilibrium to the
right ?
(A) A catalyst is added to the system.
(B) N2 is added at constant volume. (我是這個選項不會 XDD")
(C) The volume is decreased.
(D) The temperature is increased.
。 。
4.At 25 C , E cell = 1.47 V for the voltaic cell:
2+ 2+
V (s) | V (1M) || Cu (1M) | Cu (s)
(A)V (s) is the anode.
(B)V (s) is the negative electrode. (正負極我常搞混 ，怎麼簡單扼要判斷呢?!)
(C)Electrons flow from V (s) to Cu (s).
(D)The cell potential (E cell) of the reaction is zero at equilibrium.
5.Which of the following involve(s) in an increase in the entropy of the
system ?
(A)grinding a large crystal of KCl to powder (這選項的意思，不是很懂@@")
(B)Br (g) -> Br2 (l)
(C)O2(298K) -> O2(373K)
(D)NH3 (1atm , 298K) -> NH3 (3atm , 298K) (這個講一下好了^^)
(E)mixing benzene with toluene (Both have similar intermolecular forces)
( (E)選項還是無法理解!!)
6.Which of the following statements is(are) true ?
+
(A) O2 would give a bond order of 2.5
(B) C2 is diamagnetic
(C) Six electrons are involved in pi ponding in benzene , C6H6
+ -
(D) N-O bond length NO < NO2
2-
(E) The carbon-carbon bond in C2 is stronger than the one in CH3CH3
7.Which of the following statements related to alkali metals and
alkaline earth metals are incorrect?
(A)Thay can all be obtained via electrolysis of their molten salts.
(B)Their oxides can all be dissolved in the strong acid.
(C)Their carbonate salts are all fairly soluble in water.
(D)Their ions present in water are all colorless and not reactive.
(E)Alkaline earth metals can form compounds of oxidation numbers
2
+1 and +2 , because of the presence of ns electrons in their
outer shells.
(上面這題我一直不知道正解到底是什麼?!XDD")
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1F：→ Carlchen:建議 H大 改改標題 打出年份 方便後人搜尋 07/06 15:55
2F：→ Carlchen:首先，原po問的第一,二題，o810418大 講解得還不錯啊~再 07/06 16:05
3F：→ Carlchen:仔細看看他講的喔~ 07/06 16:05
4F：推 Carlchen:3.因為不會改變原有氣體的壓力，所以不影響平衡(不動) 07/06 16:11
5F：→ Carlchen:4.「電子流出」的電極，代表「電流流入」該電極，所以就 07/06 16:17
6F：→ Carlchen:是負極 07/06 16:21
7F：→ Carlchen:5.A.磨成粉墨的意思(S增大) D.加壓可以想像gas又更像液體 07/06 16:22
8F：→ Carlchen:了(S減小) E.私下猜溶解(互溶)會使S增大 07/06 16:24
9F：→ Highhuman:thx~ 07/06 16:32
10F：→ Carlchen:7.私下給 C E 07/06 16:34