5.) The number of butterflies in Southern Nevada is modeled by N = 100 ekt where t is the time in weeks. If N = 300 when t = 5, estimate the time required for this population to double in size. (Round to the nearest tenth of a week.) 6.) Use the acidity model give by pH = - log [H.]. where acidity (pH) is a measure of the hydrogen ion concentration [H.] (measured in moles of hydrogen per liter) of a solution. a) Find the pH if [H.] = 2.3 x 10-5. (Round to the nearest tenth.) b) Compute [H.] for a solution in which the PH = 4.9. (Round to eight decimal places.)