The number of water molecules present in a drop of water weighing 0.018g is

Options

A. `6.022 xx 10^(26)`
B. `6.022 xx 10^(23)`
C. `6.022 xx 10^(19)`
D. `6.022 xx 10^(20)`

Answer

D

Explanation

No. of moles = `("Moles")/("Mol. Mass") = (0.018)/(18) = 1 xx 10^(-3)`
No. of moles = `("No. of molecules")/(N_(0))`
`1 xx 10^(-3) = ("No. of molecules")/(6.022 xx 10^(23)) = 6.022 xx 10^(20)`