how many molecules are there in 30g of water?
To find the number of molecules in 30g of water, we need to use the concept of molar mass and Avogadro's number.
First, we need to determine the molar mass of water (H₂O). The molar mass of hydrogen (H) is approximately 1g/mol, and the molar mass of oxygen (O) is approximately 16g/mol. Since water has two hydrogen atoms and one oxygen atom, its molar mass is calculated as follows:
(2 * 1g/mol) + (1 * 16g/mol) = 2g + 16g = 18g/mol
The molar mass of water is 18g/mol.
Next, we'll use Avogadro's number, which states that one mole of any substance contains 6.022 × 10^23 molecules.
To find the number of moles of water in 30g, we divide the given mass by the molar mass of water:
30g / 18g/mol = 1.67 mol
Finally, we can calculate the number of molecules by multiplying the number of moles by Avogadro's number:
1.67 mol * 6.022 × 10^23 molecules/mol ≈ 1.002 × 10^24 molecules
Therefore, there are approximately 1.002 × 10^24 molecules in 30g of water.
the molar mass of water is ... 18.0 g
number of molecules is ... (30/18) * 6.02E23 = 1E24 ... 1×10^24