Question

The number of water molecules in a drop of water weighing 0.018g is- a) 6.022xl07r' b) 6.022x10n c) 6.022xlOn d) 9.9 x 10" ​

Answer 1

Answer:

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

Option C:6.022 x 10²⁰

1mole of water=18g

0.018g------? moles

Number of moles=0.018/18=0.001 moles of water.

1mole of water[ 18g ] contains 6.022 x 10²³ molecules .

0.001 moles contain ---------? molecules

=0..001x6.022 x 10²³

=6.022x10²⁰ molecules 

∴The number of water molecules in a drop of water weighing 0.018 g is 6.022x10²⁰ molecules