The number of molecules in 30g of water?
number= avagrodro's number* massgiven/molmassH2O
Physical sciences
To determine the number of molecules in 30g of water, we will need to use the concept of moles and Avogadro's number.
1. Determine the molar mass of water: The molar mass of a substance is the mass in grams of 1 mole of that substance. The molar mass of water (H2O) can be calculated by adding the atomic masses of its constituent atoms: 2 hydrogen atoms (H) with an atomic mass of approximately 1.01 g/mol, and 1 oxygen atom (O) with an atomic mass of approximately 16.00 g/mol.
Molar mass of water = (2 * atomic mass of hydrogen) + atomic mass of oxygen
= (2 * 1.01 g/mol) + 16.00 g/mol
≈ 18.02 g/mol
2. Calculate the number of moles of water: The number of moles can be calculated by dividing the given mass of water (30g) by its molar mass (18.02 g/mol).
Number of moles = Mass of water / Molar mass of water
= 30g / 18.02 g/mol
≈ 1.665 moles
3. Use Avogadro's number: Avogadro's number (6.022 x 10^23) represents the number of molecules or atoms in one mole of a substance. To find the number of molecules in 1.665 moles of water, multiply Avogadro's number by the number of moles.
Number of molecules = Number of moles * Avogadro's number
= 1.665 moles * (6.022 x 10^23 molecules/mol)
≈ 9.998 x 10^23 molecules
Therefore, there are approximately 9.998 x 10^23 molecules in 30g of water.