The mass of one molecule of water is approximately(1) 3 x 10^{-23} g(3) 1.5 x 10^{-23} g(2) 18 g(4) 4.5 x 10-23^{

The gram molecular mass of water is 18 g. The number of water molecules present in 60 g of water is:

The number of molecules present in $4.25grams$ of $N{H}_3$ is approximately:

The number of molecules in 4.25 g of ammonia is approximately

THe number of molecules in 4.25 g of ammonia is:
(a) $1.0\times {10}^{23}$ (b) $1.5\times {10}^{23}$
(c) $2.0\times {10}^{23}$ (d) $3.5\times {10}^{23}$