沒有 【段考】國二歷史上學期 權限，請先開通．

(A) A) is the mass spectrum of a 3-heptanone sample obtained under positive ion mode showing the protonated molecular species [MH]+ with a major peak at 114 + 1 ~ 115 (m/z). This 3-hetpanone sample is chromatographically pure with only a single peak on HPLC. Why does it have a small peak at 116 (m/z) on the mass spectrum? (4%)

(B)B) is the mass spectrum of an unknown organic molecule obtained under positive ion mode. Estimate the number of protons associated with this ion and the mono-isotopic mass of this molecule. Show your work. (3%)

(A) A) is the 1H NMR spectrum of 3-hetanone. Hydrogens associated with each carbon are labeled in the molecular structure shown below. Assigned each group of peaks from left to right on the NMR spectrum with lower-case letters (a-f). (4%)

(B) Homonuclear decoupling is a technique where the sample to be analyzed is irradiated at a select frequency to eliminate the effect of coupling due to certain nuclei. In other words, the signal of a select nucleus can be selectively saturated, such that this nucleus can no longer couple to neighboring nuciei. This technique helps to simplify complicated peak splitting. Irradiation at which group of protons (a-f) would result in spectral simplification in the 2.3 - 2.6 ppm range as shown in B)? Use the same lower-case letter(s) notation in A). (3%)

(a) (8 pts) Integrate the first and the second laws Tds = dU + PdV - μdn, together with the above conditions (a)(b)(c), to obtain the entropy formula S(U, V,n), which is a function of U,V and n (and T, P, μ are all eliminated).

(b) (4 pts) Suppose that a slightly different gas system satisfies (a') U= nCTδ but not (a), where the constant δ  ≠1. Show that the conditions (a')(b)(C) imply that the entropy change dS is not an exact differential.

(c) (8 pts) Modify the above chemical potential expression (c) into your (c), so that (a')(b)(c') make dS an exact differential. Obtain the entropy expression S(U,V,n) from (a')(b)(c').

(a) (2 pts) Write down the rate laws for d A(t)]/dt and d[B(t)]/dt.

(b) (3 pts) Initially [A(t = 0)] = A0, and [B(t = O) = [C(t = 0)] = 0. Apply the steady state approximation on the intermediate B, to solve the product concentration [C(t)].

(c) (5 pts) Without using the steady state approximation, solve the concentra- tion [C(t)] exactly from the rate laws. What is the condition under which the steady state approximation applies?

111年 - 國中社會考試卷：歷史151-200#112846

111年 - 國中社會考試卷：歷史151-200#112845

111年 - 國中社會考試卷：歷史101-150#112830

111年 - 國中社會考試卷：歷史51-100#112825

111年 - 國中社會考試卷：歷史1-50#112822

111年 - 暑期輔導歷史科第二堂:三代與先秦時期#110520

110年 - 台南市立民德國中110學年度第一學期 第二次成績考查 二年級歷史科試題#112056

110年 - 2021桃園市市立文昌國中八年級110 上學期社會第一次段考(期中考)歷史#108698

110年 - 2021臺北市市立新興國中八年級110 上學期歷史第三次段考(期末考)康軒#108676

110年 - 2021彰化縣縣立埔心國中八年級110 上學期歷史第三次段考(期末考)康軒#108672