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1. Carbon is important to the structure of macromolecules because it has a valence of 4. What does this mean?
2. Organize the types of bonds according to the degree to which electrons are shared between two atoms.
3. Which of the following statements best sums up the number of covalent bonds that can be formed by the four most common atoms in living things?
4. Which linking verb phrase would best connect the hydrogen bonds term in the map to one of the other terms?
5. Which of the following statements most accurately describes the relative positions of the shared electrons in methane (CH4) and ammonia (NH3)?
6. About twenty-five of the ninety-two natural elements are known to be essential to life. Which four of these twenty-five elements make up approximately 96 percent of living matter?
7. Why is each element unique with respect to its chemical properties? Each element has a distinctive _____.
8. Knowing the atomic mass of an element allows inferences about which of the following?
9. Carbon-12 is the most common isotope of carbon and has a mass number of 12. However, the average atomic mass of carbon found on a periodic table is slightly more than 12 Daltons. Why?
10. From its atomic number of 15, it is possible to predict that the phosphorus atom has _____.
11. A covalent chemical bond is one in which _____.
12. Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)?
13. Bonds between two atoms that are equally electronegative are _____.
14. A covalent bond is likely to be polar when _____.
15. What is the difference between covalent bonds and ionic bonds?
16. What element has properties most similar to carbon?
17. How many electrons are involved in a single covalent bond?
18. Elements found on the left side of the periodic table contain outer shells that are _____; these elements tend to form _____ in solution.
19. An atom has four electrons in its valence shell. What types of covalent bonds is it capable of forming?
20. Which functional group is commonly called an acid group and donates H ions to solutions at biological pH?
21. Which functional group typically acts as a base at biological pH?
22. Which statement best explains the physical basis for why oil (molecules containing only carbon and hydrogen) and water do not mix?
23.The hydrogen bonds among water molecules endow water with which property?
24.A substance that gives up a proton during a chemical reaction, raising the hydrogen ion concentration of water, is most appropriately called _____.
25.Which kinds of bonds are present in a single water molecule?
26. Which statement most accurately describes the relative potential energies (P.E.) of the electrons in the following molecules: H2, O2, and H2O?
27. Which statement best explains the energy transformation that occurs when methane burns (CH4 + 2 O2 → CO2 + 2 H2O)?
28. What type of energy is stored in the chemical bonds of a molecule?
29. The first law of thermodynamics states that _____.
30. Which functional group is least polar?
31. Which functional group contains nitrogen?
32. If water were a linear (not bent) molecule, electrostatic interactions between water molecules would be much weaker. Why?
33. Which statement best explains the physical basis for why oil (molecules containing only carbon and hydrogen) and water do not mix?
34. What is the pH of an aqueous solution with the hydronium ion concentration [H3O+] = 2 x 10-14 M ?
35. What is the molar concentration of [H3O+] in a cola that has a pH of 3.120?
36. How would the properties of the octane molecule shown in the figure be affected by adding hydroxyl groups?
37. Which kinds of bonds are present in a single water molecule?
38. A substance that gives up a proton during a chemical reaction, raising the hydrogen ion concentration of water, is most appropriately called _____.
39. The hydrogen bonds among water molecules endow water with which property?
40. Water has a high specific heat because of the _____.
41. Which of the following is a property of liquid water? Liquid water _____.
42. A solution with a pH of 5 has how many more protons in it than a solution with a pH of 7?
43. In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by _____.
44. The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called?
45. The partial negative charge in a molecule of water occurs because _____.
46. A strong acid like HCl _____.
47. One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+), as noted below. H2CO3HCO3- +H+
48. Which of the following is true for this reaction? 3H2 +N22 NH3
49. Which of the following correctly describes all chemical equilibrium?
50. Consider the following reaction at equilibrium: CO2 + H20H2CO3 What would be the effect of adding additional H2CO3?
51. If an underwater volcano bubbled additional CO2 into the ocean, would this sequence of reactions be driven to the left or the right?
52. How would this affect the pH of the ocean?
53. Place molecular oxygen (O2), magnesium chloride (MgCl2), and carbon dioxide (CO2), on the electron-sharing continuum from equal sharing of electrons to full transfer of electron.