A proposed laboratory scale cylindrical polymerization reactor to make high density polyethylene (HDPE) needs to be designed and constructed. The maximum design temperature and pressure of the reactor are 200 oC and 25 MPa, respectively. The reactor is used 4 times per day and must be designed for a minimum lifetime of 20 years. The inside diameter and wall thickness of the reactor are 300 mm and 10 mm, respectively. To meet safety regulations, a safety valve will be installed if the pressure exceeds 22 MPa, which will cause a maximum

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.