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Four allotropes of carbon, labelled W, X, Y and Z, are described in the table. Which row correctly identifies each allotrope? A. Diamond: Y, Graphite: W, Graphene: Z, Fullerene: X B. Diamond: Y, Graphite: Z, Graphene: W, Fullerene: X C. Diamond: Z, Graphite:…
The displayed formula below shows part of the chain of an addition polymer. (i) Deduce the structural formula of the monomer used to build this polymer. (ii) Describe one chemical property responsible for this type of polymer being a useful material.
The compound X shown below occurs naturally in cocoa and coffee and is used as a flavouring agent. (i) State the name of the functional group found in compound X. (ii) Deduce the IUPAC name of X. (iii) Deduce how many signals the NMR spectrum of X…
But-2-ene and other alkenes serve as starting materials for a wide range of compounds. (i) Predict the product formed when but-2-ene reacts with bromine. (ii) Describe how this reaction proceeds at the mechanistic level, drawing curly arrows for each…
When 1-bromopropane is warmed with aqueous sodium hydroxide, NaOH(aq), propan-1-ol is formed. (i) State the name given to this reaction's mechanism. (ii) Draw the structure of the transition state that occurs during this mechanism. (iii) Deduce the rate…
Several stereoisomers exist among the dichloroalkenes of molecular formula C4H6Cl2. (i) Draw the structural formula of cis-2,3-dichlorobut-2-ene. (ii) Outline why the cis-isomer of 2,3-dichlorobut-2-ene is polar, whereas the trans-isomer is not. (iii)…
trans-But-2-ene reacts with hydrogen in the presence of a nickel catalyst to form butane. C4H8(g) + H2(g) → C4H10(g) (i) Calculate, in kJ, the enthalpy change of this reaction from the bond enthalpies in section 12 of the data booklet. (ii) Calculate,…
A paper chromatogram is shown. The distances marked were measured along the paper. What is the retardation factor, RF, of compound Y? A. 0.40 B. 0.60 C. 0.70 D. 1.67
Hydrogen fluoride boils at 20 °C, whereas hydrogen chloride boils at −85 °C. Which type of intermolecular force accounts for the much higher boiling point of hydrogen fluoride? A. Hydrogen bonding B. Dipole-dipole forces C. London (dispersion) forces D.…
(i) State the products of the overall reaction. (ii) Sketch the energy profile for this reaction on the axes below. Label the reactants, the products, the transition states and the intermediate. (iii) Deduce the rate equation for the overall reaction.