The density of liquid (mol.wt. `= 70`) is `1.2 g mL^(-1)`. If `2 mL` of liquid contains `35` drops, the number of molecules of liquid in one drop are:

Options

A. `(1.2)/(35) xx N_(A)`
B. `(1)/(35) xx N_(A)`
C. `(1.2)/(35^(2))xxN_(A)`
D. `1.2 N_(A)`

Answer

C

Explanation

` :' 35 "drop" = 2mL`
`:. 1 "drop" =(2)/(35)mL=(2)/(35)xx1.2 g`
No. of molecules
`(N_(A)xx2xx1.2)/(35xx70)=(1.2)/(35^(2))xxN_(A)`