Answer
First of all, we need to find out the mass of water:
$Mass \space of \space water=2.56mL\times \frac{1.00g}{1.00mL}=2.56g$
Now, we can determine the number of moles as follows:
$2.56g\space H_2O\times \frac{1mol\space H_2O}{18.016g\space H_2O}\times \frac{6.022\times 10^{23}molecules\space H_2O}{1mol\space H_2O}=8.56\times 10^{22}moleules$
Work Step by Step
First of all, we need to find out the mass of water:
$Mass \space of \space water=2.56mL\times \frac{1.00g}{1.00mL}=2.56g$
Now, we can determine the number of moles as follows:
$2.56g\space H_2O\times \frac{1mol\space H_2O}{18.016g\space H_2O}\times \frac{6.022\times 10^{23}molecules\space H_2O}{1mol\space H_2O}=8.56\times 10^{22}moleules$