How many moles of
salt (NaCl) is 28.7
grams?

0.491 mol NaCl

Explanation:

Convert from grams to moles using the molar mass of NaCl:

28.7 g NaCl x 1 mol NaCl/58.44 g NaCl = 0.491 mol NaCl

The molar mass (58.44 g) can be found from adding the molar masses of the individual elements (Na and Cl); the g NaCl will cancel out (dimensional analysis), leaving you with mol NaCl.

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.