For a certain endothermic reaction, the activation energy is numerically equal to twice the enthalpy change of reaction. Which reaction pathway diagram is correct for this reaction?

3.6.1.1 describe hydrogen bonding, limited to molecules containing N–H and O–H groups, including ammonia and water as simple examples

3.6.1.2.1 its relatively high melting and boiling points

3.6.1.2.2 its relatively high surface tension

3.6.1.2.3 the density of the solid ice compared with the liquid water

3.6.2 use the concept of electronegativity to explain bond polarity and dipole moments of molecules

3.6.3.1 describe van der Waals’ forces as the intermolecular forces between molecular entities other than those due to bond formation, and use the term van der Waals’ forces as a generic term to describe all intermolecular forces

3.6.3.2.1 instantaneous dipole – induced dipole (id-id) force, also called London dispersion forces

3.6.3.2.2 permanent dipole – permanent dipole (pd-pd) force, including hydrogen bonding

3.6.3.2.3 tdescribe hydrogen bonding and understand that hydrogen bonding is a special case of permanent dipole – permanent dipole force between molecules where hydrogen is bonded to a highly electronegative atom

3.6.3.3 describe hydrogen bonding and understand that hydrogen bonding is a special case of permanent dipole – permanent dipole force between molecules where hydrogen is bonded to a highly electronegative atom

3.6.4 stae that, in general, ionic, covalent and metallic bonding are stronger than intermolecular forces