Caffeine (C8H10N4O2) is a weak base that is related to ammonia. For the purposes of this question, we will abbreviate the formula of caffeine
to CafN (producing cafNH+ in solution).
For a 0.70 M solution of CafN (Kb = 4.1 x 10-4), :

b) Determine the concentration of H3O+ and OH-. Show all your
entire process. [4]

c) Determine the pH and pOH. Show your work. [2]

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.