How Many Water Molecules in a Glass?

[chawkdee]

Homework Statement

A glass of water has a volume of 6.0 x 10*-4 cubic metres.
How many moles of water molecules are there in the glass?

Homework Equations

The Attempt at a Solution

I know it has something to do with Avogadro’s number but can’t figure out exactly what to do.

The weight of the water molecules will equal 6.0 x 10*-4 kg, right?
The molecular mass of water molecule is 18.0153 u.

So would it be 0.0006 kg divided by 18.0153u to give the nuber of moles?
Then with the number of moles, multiply by avogadros number to get the number of molecules?


Which gives me 2 x 10*19 molecules?

Any correction or verification greatly appreciated

 

[Saladsamurai]

Homework Statement

A glass of water has a volume of 6.0 x 10*-4 cubic metres.

...
The weight of the water molecules will equal 6.0 x 10*-4 kg, right?

Hey there chawkdee Cubic meters are not a unit of weight are they? They are a unit of volume.

How can you relate the volume of water to its mass?