Question

7 Marks The structure of cytosine, one of the four is one of the four main bases found in DNA is shown below. Assign the bonding geometry around each numbered atom in cytosine. 3 HC6 HC NH2 Bonding geometry Atom NI C2 N3 Identify the strongest type of intermolecular forces present in the following four compounds and using this information explain the order of the melting points Melting point (C) -220 Strongest Intermolecular force Species F2 -129 NF3 -87 HBr 98 CH3OH Explanation

Answer 1

for hy briclizah'n, sigma) banel and it loes tone pair COnmclerecl if Part in Y ESOno1e not Sp Trigon Planar) Trigonat planar Spi Spe N3 bas one lone Pas t i vancder waal terce (dipersin) i Pole -li PDle Laterachin Interachin Di pele elpole CH3on Intermolecular) Explanahin is fosmed behoeen f bond liffer ent element there Hhen oill be dpole cleprle nterachan anel f bond is behween Same a hom ten VanclerDee H Connectel usth a, t orN take part Dreles af Streayfh ot Force: Mydnoyen bond pble vanclarea Hence merti oint areler L1,on) Hor> KE