The molar mass of HCl is 36.5 g/mol, and the average mass per HCl molecule is 36.5 u. Use the fact that 1 u = 1.6605 * 102 24g to calculate Avogadro's number.

Verified step by step guidance

1. Convert the average mass per HCl molecule from atomic mass units (u) to grams. Since 1 u = 1.6605 x 10^-24 g, multiply the mass of one HCl molecule in u by this conversion factor.
2. Calculate the number of HCl molecules in one mole. Since the molar mass of HCl is 36.5 g/mol, divide this value by the mass of one HCl molecule in grams to find the number of molecules per mole.
3. Recognize that the number of molecules per mole calculated in the previous step represents Avogadro's number, which is the number of constituent particles (usually atoms or molecules) in one mole of a substance.
4. Verify the units to ensure that the result from the calculation is dimensionally consistent, with Avogadro's number being a dimensionless quantity representing a count of particles.
5. Compare the calculated value of Avogadro's number with the known value (approximately 6.022 x 10^23 mol^-1) to check the accuracy of your calculation.

Key Concepts

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all the atoms in a molecule. For HCl, the molar mass is 36.5 g/mol, indicating that one mole of HCl weighs 36.5 grams.

Atomic Mass Unit (u)

The atomic mass unit (u) is a standard unit of mass used to express atomic and molecular weights. One atomic mass unit is defined as one twelfth of the mass of a carbon-12 atom. In this context, the average mass of an HCl molecule is given as 36.5 u, which corresponds to its molar mass in grams per mole.

Avogadro's Number

Avogadro's number is a fundamental constant that represents the number of particles (atoms, molecules, etc.) in one mole of a substance, approximately 6.022 x 10²³. It can be calculated using the relationship between molar mass and the mass of a single molecule, allowing for conversions between mass and the number of molecules.