What must occur in order for a chemical reaction to be specifically classified as endothermic instead of exothermic?
2 answers:
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Answer:
are a result of hydrogen bonding.
Explanation:
The <em>surface tension</em><em> is the amount of energy required to stretch or increase the surface of a liquid by a unit area</em>. <u>Liquids that have strong intermolecular forces also have high surface tensions.</u> Thus, because of hydrogen bonding, water has a considerably greater surface tension than most other liquids.
Another example of surface tension is capillary action. A thin film of water adheres to the wall of the glass tube. The surface tension of water causes this film to contract, and as it does, it pulls the water up the tube. Two types of forces bring about capillary action.
One is <em>cohesion</em><em>, which is the intermolecular attraction between like molecules (in this case, the water molecules)</em>. The second force, called <em>adhesion</em><em>, is an attraction between unlike molecules, such as those in water and in the sides of a glass tube</em>. If adhesion is stronger than cohesion, the contents of the tube will be pulled upward. This process continues until the adhesive force is balanced by the weight of the water in the tube.
This <u>characteristics of water are a consequence of a particularly strong type of intermolecular attraction, called the </u><u>hydrogen bond</u><u>, which is a special type of dipole-dipole interaction between the hydrogen atom in a polar bond, such as N-H, O-H, or F-H, and an electronegative O, N, or F atom.</u>
