2. How many moles of water are in 3.80 * 10 ^ 23 molecules of H2O

Why are people not able to skip a dive to the deepest part of the ocean

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

Amixture initially contains a, b, and c in the following concentrations: [a] = 0.300 m , [b] = 1.05 m , and [c] = 0.550 m . the following reaction occurs and equilibrium is established: a+2b⇌c at equilibrium, [a] = 0.140 m and [c] = 0.710 m . calculate the value of the equilibrium constant, kc.