一些化學反應的題目
這學期課本都原文的，原理還在摸索中，老師就很快的出作業出來
實在是不懂阿...
哪個好心大大能幫我解題，謝謝><
1. 有一化學反應式包含化學劑量方程式 A+B=2R，則此反應式的次序為何?
2.以化學反應式2NO2+(1/2)O2=N2O5為前提，則組成的比例及三個反應要素消去的關係為何?3.有一包含化學劑量方程式(1/2)A+B=R+(1/2)S的反應式有下列比例式：
-rA= 2CA0.5CB，則若化學劑量方程式為A+2B=2R+S，該反應式的比例式為何?
4.某一化學反應式符合比例式-rA= 0.005CA2(單位:mol/cm3.min)的比例，若它的濃度以每公升X莫耳、時間以小時為單位表示，則該反應式的固定比例之數值與單位為何?5.氮氧化物的分解被發現以下列反應式進行：N2O→N2+(1/2)O2，(題目給的公式:-rN2O=k1[N2O]2/1+k2[N2O])，則此反應式與二氧化氮有關的次序和總反應式次序為何?6. 高溫分解的乙烷以一莫耳300000焦耳的活化能同步進行，則它分解的速度於650度C時較500度C快多少?7.有一1100K的n壬烷，以與1000K相較下快20倍的速度高溫分解(分解為較小的分子)。找出此壬烷分解的活化能。
原文:
1.A reaction has the stoichiometric equation A+B=2R.
What is the order of reaction?
2.Given the reaction 2NO2+(1/2)O2=N2O5，what is the relation between the rates of formation and disappearance of the three reaction components?
3.A reaction with stoichiometric equation (1/2)A+B=R+(1/2)S has the following rate expression (題目給的公式:-rA= 2CA0.5CB)
What is the rate expression for this reaction if the stoichiometric equation is written as A+2B=2R+S?
4.A certain reaction has a rate given by (題目給的公式:-rA= 0.005CA2….mol/cm3.min)
If the concentration is to be expressed in mol/liter and time in hours，what would be the value and units of the rate constant?
5.The decomposition of nitrous oxide is found to proceed as follows:
N2O→N2+(1/2)O2，….-rN2O=k1[N2O]2/1+k2[N2O]
What is the order of this reaction with respect to N2O，and overall?
6.The pyrolysis of ethane proceeds with an activation energy of about 300kJ/mol.
How much faster is the decomposition at 650○C than at 500○C?
7.A 1100-K n-nonane thermally cracks(breaks down into smaller molecules) 20 times as rapidly as at 1000K. Find the activation energy for this decompo-sition.
麻煩大大了，謝謝QQ
2 個解答
- 小白Lv 79 年前最佳解答
你還是打原文吧，第１２３題的中文實在看不懂。
2011-03-13 23:40:29 補充：
1. 若A+B->2R為基本反應(elementary reaction)，則此反應為二級反應。
order是指反應級數，不是反應次序。
2. 由反應式可知，每消耗2莫耳NO2，伴隨消耗0.5莫耳O2，生成1莫耳N2O5，所以-r(NO2) = -4r(O2) = 2r(N2O5)
3. 反應速率表示式的寫法，與反應式係數無關，所以即使反應式左右各乘以２，反應速率式依然是 -rA = 2CA^0.5CB
4. -rA = 0.005CA^2 mol/cm3-min
其中CA單位是mol/cm3，速率常數 = 0.005 cm3/mol-min = 0.005 × 0.001 / (1/60) L/mol-hr = 3 × 10^-4 L/mol-hr
5. 對N2O而言，分解反應為2級，就整體而言，分解反應為1級（考慮逆反應）。
6. 7. 兩題須參照Arrhenius Equation，設活化能不受溫度影響。
圖片參考：http://upload.wikimedia.org/math/f/c/b/fcbf7210f17...
6.
k1 = A×exp(Ea/RT1) = A×exp[-300000/(8.314×500)]
k2 = A×exp(Ea/RT2) = A×exp[-300000/(8.314×650)]
k2 / k1 = exp[300000/8.314 × (1/500 - 1/650)] = 1.71 × 10^7 倍
7. k2/k1 = 20 = exp[Ea / 8.314 × (1/1000 - 1/1100)]
Ea = 2.74 × 10^5 J
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