Calculator Allowed: Yes



Transcription of this question: Ethyne, C2H2, reacts with oxygen in welding torches.(a) Write an equation for the complete combustion of ethyne.0)(ii)Deduce the Lewis (electron dot) structure of ethyne.Compare, giving a reason, the length of the bond between the carbon atoms inethyne with that in ethane, C2H6.(iii) Identify the type of interaction that must be overcome when liquid ethyne vaporizes. [1](c)Ethyne reacts with steam.(g) + H20(g) C2H40(g)Two possible products are:and0)(ii)State the name of product B, applying II_JPAC rules.Determine the enthalpy change for the reaction, in kJ, to produce A using section11 of the data booklet.(iii) The enthalpy change for the reaction to produce B is —213kJ.Predict, giving a reason, which product is the most stable.(iv)0.8060.402The IR spectrum and low resolution IHNMR spectrum of the actual productformed are shown.3000IR spectrum2000Wavenumber / cm-l1000[Source: NIST Chemistry WebBook SRD 69https:mwebbook_nist_gov/chemistry DOE https:/ 18434/T4D303http:Wwebb03k_nist_govcgifinchi10Chemical shift / ppmDeduce whether the product is A or B, using evidence from these spectratogether with sections 26 and 27 of the data booklet.Identity of product:One piece of evidence from IR:One piece of evidence from IHNMR:(v)Deduce the splitting pattern you would expect for the signals in a high resolutioniH NMR spectrum.[2][2]2.3ppm:9.8ppm:(d)Product B, CH3CHO, can also be synthesized from ethanol.(i) Suggest the reagents and conditions required to ensure a good yield of product B.[2]Reagents:Conditions:(ii)(iii)Deduce the average oxidation state of carbon in product B.Explain why product B is water soluble.

Leave a Reply