Question

Number of water molecules present in one drop of water of volume 0.02 mL is(the answer should be 6.67 x 10*20) pls provide detailed solution ​

Answer 1

Explanation:

ANSWER

As we know that,

Density=

volume

mass

⇒mass=density×volume

Density of water =1g/ml

Volume of water =0.0018mL(Given)

∴ Mass of 0.0018mL water =1×0.0018=0.0018gm

Molar mass of water =18gm/mol

Number of moles in 0.0018gm of water =

Molar mass

Given mass

=

18

0.0018

=0.0001 mole

As we know that,

Number of molecules of water in 1 mole =6.022×10

23

molecules

∴ Number of molecules of water in 0.0001 mole =6.022×10

3

×0.0001=6.023×10

19

Hence, the number of water molecules present in a drop of water (volume =0.0018ml) at room temperature are 6.023×10

19

.