A25.00 ml sample containing an unknown amount of al3+ and pb2+ required 17.14 ml of 0.04907 m edta to reach the end point. a 50.00 ml sample of the unknown was then treated with f− to mask the al3+ . to the 50.00 ml sample, 25.00 ml of 0.04907 m edta was added. the excess edta was then titrated with 0.02064 m mn2+ . a total of 26.5 ml was required to reach the methylthymol blue end point. determine pal3+ and ppb2+ in the unknown sample.

Many bird species build nests in which they raise their offspring. one of these species is known as the magnolia warbler. breeding pairs of magnolia warblers build nests out of pieces of grass and twigs. the female warbler will then lay her eggs in the nest and sit on the eggs for a few weeks until they hatch. after the offspring have hatched, the female will continue to sit on the newborn chicks to keep them warm. both the male and the female bring food for the offspring to eat until the young are mature enough to find food on their own. which of these most likely describes why birds such as the magnolia warbler build nests in which to raise their offspring? a. nest building decreases the amount of energy used by the parent birds to raise their offspring to adulthood. b. nest building increases the probability that the offspring will survive and eventually produce offspring of their own. c. nest building decreases the amount of food that the offspring require the adult birds to provide. d. nest building increases the probability of the offspring being located by airborne predators.