代做SLE210 – Chemistry the Enabling Science Exam paper 1帮做R编程

日期：2024-06-01 05:25

Practice Examination paper

School of Life and Environmental Sciences

Trimester 1

Unit Code: SLE210

Unit Name: Chemistry the Enabling Science

Paper name: Exam paper 1

Wave and particle properties of electron 10 mark

Q1. Microwave ovens use radiation with wavelength of 12.5 cm. What is the frequency, and energy in kJ/mol, of this radiation? 5 mark

Q2. List all possible quantum sets for an electron in the 4p quantum level. 5 mark

Chemical bonding and molecular structure 10 mark

Q3. Capsaicin is the molecule responsible for the hot spiciness of chillies:

Using your knowledge of valence bond theory please answer the following:

a.    How many π bonds does capsaicin have? 1 mark

b.   Which orbitals are used for bonding by each of the labelled atoms? 5 mark

c.    What are the bond angles around each of the labelled atoms? 1 mark

Q4. Which of N2  or N2+  has the stronger bond? Use molecular orbital configurations (molecular orbital theory) to justify your selection. 3 mark

Transition metals and their complexes 10 mark

Q5. Why is manganese(VII) [in potassium permanganate] intensely coloured while manganese(II) is generally not? 5 mark

Q6. How can complexation be used for gold mining? 5 mark

Electrochemistry 10 mark

Q7. Explain how cathodic protection works using a suitable example? 3 mark

Q8. The following reactions (1) and (2) are part of a lead storage battery (Eº = 2.05 V).

(1)   Pb(s) + SO42–(aq) → PbSO4(s) + 2e–

(2)   PbO2(s) + 4H+(aq) + SO42–(aq) + 2e– → PbSO4(s) + 2H2O(l)

What is the change in Gibbs free energy of a cell in this battery upon discharging? Please provide the answer in kJ. 7 mark

Spectroscopy                                                                                                                                         10 mark

Q9. The structure of naproxen (a nonsteroidal anti-inflammatory drug) is shown below

Determine the index of hydrogen deficiency (IHD) of naproxen, C14 H14O3. 1 mark

Q10. A) Determine the number of signals you would expect to see in the 1 H-NMR spectrum of each of the following compounds. 1 mark

B) Determine the number of signals you would expect to see in the 13C-NMR spectrum of each of the compounds in part A, question 10. 1 mark

Q11. Match each of the following compounds with the appropriate spectrum. 1 mark

Q12. The following is a 'H-NMR spectrum for one of the following compounds:

i)            Identify the compound responsible for this spectrum. 1 mark

ii)           Assign all signals to their corresponding hydrogen atoms. Give brief reasoning(s) for your answer. 3 mark

Q13. The constitutional isomers 1-penten-3-ol and 2-pentanone have the molecular formula C5 H10O. The IR spectra of these isomers are shown below.

a)    For the isomers, 1-penten-3-ol and 2-pentanone, list one major feature that appears in the IR spectrum of one compound but not the other compound. 1 mark

b)   Assign each compound to its correct infrared spectrum. 1 mark

Reaction kinetics 10 mark

Q14. For the reaction:

2 HCrO4- + 3 HSO3-  + 5 H+  → 2 Cr3+  + 3 SO42=  + 5 H2O The rate law is:

rate of reaction = k [HCrO4-] [HSO3-]2  [H+]

Give the order with respect to HSO3- 1 mark

Q15. The following data were collected for the decomposition of acetaldehyde, CH3CHO (used in the manufacture of a variety of chemicals including perfumes, dyes and plastics), into methane and carbon monoxide. The data were collected at a temperature of 530°C.

CH3CHO → CH4  + CO

Determine the average rate of reaction between 60s and 80s. 5 mark

Q16. The formation of small amounts of nitric oxide, NO, in car engines is the first step in the formation 3of smog. Nitric oxide is readily oxidised to nitrogen dioxide by the reaction:

2 NO + O2  → 2 NO2.

Determine the rate law for the reaction. 4 mark

Condensed phases and real gases 10 mark

Q17. Sketch the approximate phase diagram for Br2  from the following information: normal melting point is 265.9 K, normal boiling point is 331.9 K, triple point is at p=5.87 x 103  Pa and T=265.7 K. Label the axes and   the area where each phase is stable. 3 mark

Q18. A gas mixture contains N2  (X = 0.7422), O2  (X = 0.1992), Ar (X = 5.340 x 10–3), CO2  (X = 1.240 x 10–2), and He (X = 4.086 x 10–2). Calculate the partial pressure of Ar at an atmospheric pressure of 101.3 kPa. 5 mark