Chemistry Questionnaire Essay

What is meant by the term cis-trans isomerism? How m whatsoever cis-trans isomers be present in Structure I? Draw any 2 potential cis-trans isomers. (iii) State the material state of this lipoid at room temperature. Explain your answer. 9 (b) bring up a possible identity for separately of the organic compounds A-E below. Explain your sourceing and issue balanced equations for the reactions involved where possible. i) A, C11H14O2 is a indifferent(p) compound. Hydrolysis of A gives B, C7H6O2 which is a white precipitous and C, C4H10O which does not decolourise corrosiveified super acid manganate(VII) on heating. (ii) D, C4H10O2 reacts with 2 moles of sodium coat, but not with secure sodium change. On simmering to a lower place reflux with sedimentary potassium manganate(VII), D gives a compound, E, C4H6O3. E reacts with alkalescent sedimentary iodine to give a yellow precipitate and evolves carbon dioxide when solid sodium carbonate is added.Draw geomorphological mictu rateulae of the products of the reactions among glutamic acid and I aqueous NaOH II aqueous HCl (ii) Draw the morphologic formula of a dipeptide formed between glutamic acid and phenylalanine, showing the ionic form in which it would exist at pH 10. 4 Total 20 5 3 (a) Iron(III) chloride is a Stygian brownish solid which dissolves in weewee to give an acidic solution. This solution is utilize to etch, i. e. dissolve, unwanted copper from printed circuit boards. When a copper-coated printed circuit board is immersed in aqueous iron(III) chloride, the solution turns immature blue. i) Explain, with the aid of an equation, wherefore aqueous iron(III) chloride is acidic. (ii) Use the Data cusp to explain why iron(III) chloride etches copper. Give a relevant equation to explain the greenish blue solution observed. (iii) signal what happens to the overall E0 value if the thickness of the copper finis is increased.Anhydrous aluminium chloride behaves similarly as anhydrous iron( III) chloride in that they sublime right away when heated. When 1. 56 g of aluminium chloride was hardened in an evacuated vessel of volume 1. 00 dm3 at 1800C, the pressure produced was 32. kPa. (i) train the app arent congenator molecular mass of the aluminium chloride under(a) the stated conditions. (ii) In the vapour phase, aluminium chloride partially exists as a dimer. using your answer obtained for b(i), calculate the percentage of the dimer under the stated conditions. (iii) Suggest a condition why the dimerisation process of aluminium chloride is exothermic. 6 (iv) Predict, giving a reason in each case, the effect on the resemblance of dimer in the equilibrium mixture if I the pressure is lowered, II the temperature is lowered.MgO(s) + CO2(g) ?H? = +117 kJ mol-1 ?S? = +175 J mol-1 K-1 8 (i) why does the entropy increase when milligram carbonate decomposes? (ii) envision the standard Gibbs free zippo change, ? G? , for the putrefaction of magnesium carbonate. foo tnote on the spontaneity of the decomposition of magnesium carbonate at room temperature. (iii) take for granted that ? H? and ? S? for the reaction are independent of temperature, calculate the temperature at which the decomposition reaction becomes feasible. (iv) Compare the ease of caloric decomposition of magnesium carbonate with barium carbonate. 8 Turn over 4 (d) Suggest a simple chemical sample to distinguish between each checkmate of compounds. For each test, give reagents and conditions, and state what would be seen with each compound.The dissociation reactions and Ka values of carboniferous acid are given below. H2CO3 HCO3- + H+ Ka1 = 4. 2 x 10-7 mol dm-3 HCO3- CO32 + H+ Ka2 = 4. 8 x 10-11 mol dm-3 0. 10 mol dm-3 aqueous NaOH is added slowly to 20. 0 cm3 of carbonic acid and the change in pH is followed and shown below. pH x x B x A x x 10 20 30 40 10 Vol of aqueous NaOH added / cm3 (i) Calculate the initial pH of the carbonic acid, stating any assumptions you make. (ii) Calculate the pH at the inaugural equivalence advert, A. (iii) What is the pH at point B? Give a reason for your answer. 6 Turn over 5 (b) Maintenance of pH is vital to the cells of all living organisms because enzyme occupation is influenced by pH. For instance, protection from harmful pH change in the business line melodic line plasma is provided by the hydrogencarbonate/carbonic acid placement (HCO3-/H2CO3). At 370C, the temperature of the human body, pH of blood plasma is 7. 4. i) Explain, with relevant equations, how the hydrogencarbonate/carbonic acid system regulates the pH of blood plasma. (ii) Calculate the ratio of HCO3-/H2CO3 for maintaining the optimum pH of blood plasma. 4 (c) Describe two differences in physical properties between transition metals and a s-block metal such as magnesium, suggesting reasons for these differences based on their atomic structures. 3 11 (d) The oxidation of manganese(IV) oxide in alkaline solution in manner produces green manga nate(VI) ion, MnO42-. When manganate(VI) is added to a dilute acid, a purple solution and dark brown solid manganese(IV) oxide reforms.