81) When a small amount of HCl or NaOH is added to a solution of Na2HPO4, the pH of the solution barely changes. Based on these observations, all of the following are true concerning the compound Na2HPO4, except A) Na2HPO4 is able to accept extra hydrogen ions from the HCl. B) Na2HPO4 is able to donate hydrogen ions to the OH- from NaOH. C) Na2HPO4 adsorbs excess H+ and OH- directly onto the surface of its crystalline structure. D) Na2HPO4 is a salt formed from reacting a strong base with a weak acid. E) Na2HPO4 acts as a buffer. 82) Carbohydrates, lipids, and proteins are classified as A) organic molecules. B) inorganic molecules. C) acids. D) salts. E) bases. 83) A functional group is best described as reoccurring clusters of A) elements that occur in a salt. B) atoms that greatly influence the chemical properties of molecules they are part of. C) atoms that function in the body. D) elements that form at high pH. E) amino acids in a globular protein. 84) Artificial sweeteners A) are naturally similar to sugars. B) are always some form of carbohydrate. C) are usually not broken down by the body. D) are inorganic sugar substitutes. E) provide the same number of calories as an equivalent amount of sucrose. 85) Fructose is A) a hexose. B) an isomer of glucose. C) found in male reproductive fluids. D) a carbohydrate. E) All of the answers are correct. 86) Molecules that have the same molecular formula but different structural formulas are called A) isotopes. B) isomers. C) isozymes. D) isotypes. E) isomoles. 87) The most important metabolic fuel molecule in the body is A) sucrose. B) caffeine. C) protein. D) vitamins. E) glucose. 88) A polysaccharide that is formed in liver and muscle cells to store glucose is A) lactose. B) cellulose. C) glycogen. D) sucrose. E) fructose. 89) The group of organic compounds containing carbon, hydrogen, and oxygen in a near 1:2:1 ratio is defined as a A) carbohydrate. B) lipid. C) protein. D) nucleic acid. E) saturated fat. 90) An example of an organic substance is: A) sucrose B) carbonic acid C) sodium chloride D) oxygen E) nitric oxide