# Question b19de

Jul 22, 2017

The number of water molecules is maximum in b) 18 mol of water.

#### Explanation:

We must calculate the number of molecules in each case.

a) 1.8 g of water

$\text{Molecules of water}$

= 1.8 color(red)(cancel(color(black)("g water"))) × (1 color(red)(cancel(color(black)("mol water"))))/(18.02 color(red)(cancel(color(black)("g water")))) × (6.022 × 10^23 color(white)(l)"molecules water")/(1 color(red)(cancel(color(black)("mol water"))))

= 6.02 × 10^22color(white)(l) "molecules water"

b) 18 mol of water

$\text{Molecules of water}$

= 18 color(red)(cancel(color(black)("mol water"))) × (6.022 × 10^23 color(white)(l)"molecules water")/(1 color(red)(cancel(color(black)("mol water"))))

= 1.08 × 10^25color(white)(l) "molecules water"

c) 18 g of water

$\text{Molecules of water}$

= 18 color(red)(cancel(color(black)("g water"))) × (1 color(red)(cancel(color(black)("mol water"))))/(18.02 color(red)(cancel(color(black)("g water")))) × (6.022 × 10^23 color(white)(l)"molecules water")/(1 color(red)(cancel(color(black)("mol water"))))

= 6.02 × 10^23color(white)(l) "molecules water"#

d) 18 molecules water

We have 18 molecules of water.

There are the most water molecules in Option b).