Calculate the mass of `12.044 xx 10^(25)` molecules of oxygen `(O_(2))`.

Calculate the mass of 1.51 xx 10 ^(23) molecule of H_2O .

Calculate the mass of 1.2044 xx 10^(23) molecules of O_(2) ("Atomic mass of O"=16u) .

Calculate the mass of 12.0 xx 10^(14) atoms of hydrogen .

Calculate the volume occupied by 4.045 xx 10^(2) molecules of oxygen at 27^(@)C and having a pressure of 700 torr.

Calculate the weight of 12.044 xx 10^(23) atoms of carbon.