Question

4. Ethylene glycol is the major component of antifreeze. It is slightly viscous. Pen same molecular weight, is a nonviscous liquid. Pentane, which has about the a. List all IMFs present for each substance. (z-2.1,자=2sxī НН НН Ethylene glycol, IMFs: H HH H H pentane, IMFs: disperson b. Explain the difference in viscosities between ethylene glycol and pentane using IMFs. Be detailed - explain at the molecular level. How do the specific IMFs lead to the observed viscosities? Tn stonger the INF ,the sthongcr the ucocityw A -bond s tionges tnan slon , the v fo rc ethylcn glyols areator tnan pcntarc jisuouit eut 514 c. Which substance would you expect to have a higher boiling point-ethylene glycol or pentane? Why? How do IMFs influence boiling point? Ety lene lycol beuse He strangit tue lound , the nghe, tebeding fo nt.wh1?

Answer 1

#4: (a): Ethylene glycol has hydrogen bonding, dipole-dipole interaction and dispersion force.

Pentane has only dispersion force.

(b): Due to stronger hydrogen bonding in ethylene glycol, the molecules are strongly attracted towards each other. Stronger attraction gives more resistance to the flow of molecules of ethylene glycol leading to increase in viscosity. Hence ethylene glycol has higher viscosity than pentane.

(c): Due to a stronger hydrogen bonding in ethylene glycol, it has higher boiling point than pentane.

Due to stronger IMF, the ethylene glycol molecules are strongly attracted to each other. As a result more energy is required to separate the molecules from each other to evaporate them. To supply more energy, the boiling point must be higher.