How can you force a solid compound to the bottom of a melting point capillary? (select all that apply.)

a. tap the closed end of the capillary on the counter
b. use a long plastic or glass tube as a drop guide
c. tap the open end of the capillary on the counter
d. use a needle to physically push it to the bottom

Explanation:

A capillary is defined as a slim tube in which a solid compound is inserted in order to detect the melting point of the solid.

In order to place the solid into the capillary, it is necessary that the compound should be finely powdered. And, one end of the capillary is closed while the other end which is open is filled with powdered solid.

We tap the closed end of the capillary so that capillary contains maximum amount of the compound.

To determine the melting point of the solid it is important to use a long plastic or glass as drop guide.

Thus, we can conclude that we force a solid compound to the bottom of a melting point capillary:

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.