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

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.

Would the answer then be 37.46 times 10^23?

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

To determine the number of molecules in a given mass of a substance, you can use the concept of moles and Avogadro's number. Here's how you can calculate the number of molecules in 112 grams of water:

1. Determine the molar mass of water: Water (H2O) consists of two hydrogen atoms and one oxygen atom. The atomic masses of hydrogen and oxygen are approximately 1 and 16 grams/mole, respectively. So, the molar mass of water is (2 x 1) + 16 = 18 grams/mole.

2. Convert the mass of water to moles: Divide the given mass (112 grams) by the molar mass of water (18 grams/mole) to obtain the number of moles. 112 g / 18 g/mol = 6.22 moles.

3. Use Avogadro's number: Avogadro's number represents the number of particles (atoms, molecules, or ions) present in one mole of a substance, which is approximately 6.022 x 10^23 particles/mol.

4. Multiply the number of moles by Avogadro's number: Multiply the number of moles of water (6.22 moles) by Avogadro's number (6.022 x 10^23 particles/mol) to find the number of water molecules.
6.22 moles x 6.022 x 10^23 molecules/mol = 3.74 x 10^24 molecules.

Therefore, there are approximately 3.74 x 10^24 water molecules in 112 grams of water.

I hope this helps! Let me know if you have any further questions.