Question

The number of molecules in a drop of water , if its voluvolume is 0.05 ml are

Answer 1

we know that

the molar mass of water = 18 gms/mol

and

the number of molecular in a molar mass of any substance would be = 6.023 x 1023 molecules

so,

1 gram of water will have = (6.023 x 1023) / 18

so,

the number of molecules in one drop (50mg = 0.05 gm) of water = [(6.023 x 1023) x 0.05] / 18

thus, we get

number of molecules = 1.673 x 10 21 molecules