Question

How many molecules are in 112 grams of water? Can you show me the proportion for how to do this? Thanks for your help :-)

Answer 1

There are 18 g of water in a mole of water and there are 6.02 x 10^23 molecules in a mole of anything. I do it this way.
112 grams H2O x (1 mol H2O/18 g H2O) x (6.02 x 10^23 molecules H2O/mole of water) ??
The first factor converts grams to moles and the second factor converts moles to molecules.
You will notice that the unit"grams water" cancel and unit "moles H2O" cancel. What unit is left? molecules water which is the unit you wanted.

Answer 2

Would the answer then be 37.46 times 10^23?

Answer 3

Yes, but I would write it has 3.74 x 10^24.