Question

In each of the following groups of substances, pick the one that has the given property. Justify your answer

a)Greatest viscosity: CH₃CH₂CH₂CH₃, HOCH₂CH₂OH or CH₃CH₂OH

b)Strongest Hydrogen bonding: PH₃, NH3, SbH₃

c)Greatest heat of vaporization: HF, HI, HBr, HCl

d)Smallest enthalpy of fusion: CO₂, Li₂O, H₂O, MgO

Answer 1

a)

Greatest viscosity : HOCH₂CH₂OH

hydrogen bonds increases the viscosity . in this molecule hydrogen bond capacity is more. so visocosity is more.

b)

Strongest Hydrogen bonding: NH3

NH3 only forms hydrogen bonding. remaining are not forming hydrogen bond.

c)

Greatest heat of vaporization : HCl

boiling point order : HF > HI > HBr > HCl .

which is having least boiling point , that has greatest heat of vapourization.

d)

Smallest enthalpy of fusion:   MgO