How many molecules of water of water are in a 821.3 g sample

It is a ok  i know i have a brain functioning well.                                                                                                                                                           

The answer to your question would be  h+ + cn– + li+ + oh– mc001-4.jpg li+ + cn– + h2o. the total ionic equation for the following reaction is  h+ + cn– + li+ + oh– mc001-4.jpg li+ + cn– + h2o.

  the volume of  0.220 m k2s    solution  required  to  completely  react with 175 ml  of 0.115m co(no3)2  calculate the moles  of co(no3)2 =  molarity x volume/1000175 x0.115/1000= 0.02  moleswrite  the reacting  equationk2s(aq)  +  co(no3)2  = 2 kno3(aq)  + cos(s)by  use  of mole ratio between k2s to co(no3)2 which  is  1: 1 the moles of k2s is therefore = 175  x0.115/1000= 0.02  molesvolume = moles/molarity=0.02/0.22=0.09  ml  of k2s