2. The following reactions:
  
are examples of
(A) acid-base reactions.
(B) unbalanced reactions.
(C) precipitation, acid-base, and redox reactions, respectively.
(D) redox, acid-base, and precipitation reactions, respectively.
(E) precipitation, redox, and acid-base reactions, respectively.

48. What mechanism leads to changes in allele frequencies due to random chance? (A) Genetic drift (B) Natural selection (C) Sexual selection (D) Neutral variation (E) inbreeding

49. A major disadvantage of using DNA or RNA sequences to identify species is that (A) it can only be used for sexually reproducing organisms. (B) it cannot be used for extinct species. (C) there are no rules for determining the number of sequence differences needed for a new species. (D) if can be misleading because many species exhibit large variation in phenotype. (E) it is expensive to sequence genomic DNA

50. Adaptive radiation is likely to have led to which of the following? (A) The divergence of a single pea aphid population into two distinct species. (B) The evolution of the horse via changes in climate and food supply. (C) The long period of equilibrium in a bat species in the Mariana Islands. (D) The 1,000 species of Drosophila found dispersed throughout the Hawaiian Islands. (E) A population of mountain goats are split because of the formation of a glacier.

1.For the reaction of sodium bromide with chlorine gas to form sodium chloride and bromine, the appropriate half-reactions are (ox = oxidation and re = reduction): (A) (B) (C)(D)(E)

3.What volume of 18.0 M sulfuric acid must be used to prepare 15.5 L of 0.195 M H2SO4 ? (A) 168 mL (B) 0.336 L (C) 92.3 mL (D) 226 mL (E) none of these

4. Air has an average molar mass of 29.0 g/ mol. The density of air at 1.00 atm and 30°C is (A) 29.0g/L (B) 40.0g/mL (C) 1.17g/L (D) 1.29g/L (E) 12g/L

5. Consider the following gas samples:Which one of the following statements is false? (A) The volume of sample A is twice the volume of sample B. (B) The average kinetic energy of the molecules in sample A is twice the average kinetic energy of the molecules in sample B. (C) The fraction of molecules in sample A having a kinetic energy greater than some high fixed value is larger than the fraction of molecules in sample B having kinetic energies greater than that same high fixed value. (D) The mean square velocity of molecules in sample A is twice as large as the mean square velocity of molecules in sample B. (E) Assumning identical intermolecular forces in the two samples, sample A should be more nearly ideal than sample B.

6.Consider the following ground state electron configuration: 1s22s22p4. Which of the ions has this ground state electron configuration? (A) (B) (C) (D)

7. Which ionization process requires the most energy? (A) (B) (C) (D)

8. Which type of spherical packing has the most unused space? (A) body-centered cubic (B) cubic closest-packed (C) cubic closest-packed and hexagonal closest-packed (D) simple cubic