Codeine is a weak organic base with a Kb = 1.6 x 10-6 C18H21NO3(aq) + H2O(l) ⇌ C18H21NO3H+(aq) + OH-(aq)

a) What is the value of pKa and pKb?
b) Calculate the equilibrium concentrations for [C18H21NO3(aq)], [C18H21NO3H+(aq)], and [OH-(aq)] for a 0.050-M solution of codeine.
c) What is the pH of the 0.050-M codeine solution?

what's the

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).