How many grams of oxygen are in 1.51 x 1023 molecules of oxygen (O2)?

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.

All of the following are part of the biosphere except

Calculate the h3o+ concentration in a solution of acetic acid if the concentration of molecular acetic acid present at equilibrium is 9.97x10-3 m and k for the dissociation is 1.86x10-5. ch3cooh(aq)+h2o(l)+> h3o+(aq)+ch3coo-(aq) show me how to get the answer.