Calculate the mass, in grams, of each sample. c. 1.8×10²³ lead atoms

Verified step by step guidance

1. Identify the given quantity: 1.8 \times 10^{23} lead atoms.
2. Recall Avogadro's number, which is 6.022 \times 10^{23} atoms/mol. This number represents the number of atoms in one mole of a substance.
3. Calculate the number of moles of lead by dividing the given number of atoms by Avogadro's number: \text{moles of lead} = \frac{1.8 \times 10^{23}}{6.022 \times 10^{23}}.
4. Find the molar mass of lead (Pb) from the periodic table, which is approximately 207.2 g/mol.
5. Calculate the mass of the lead sample by multiplying the number of moles by the molar mass: \text{mass of lead} = \text{moles of lead} \times 207.2 \text{ g/mol}.

Key Concepts

Avogadro's Number

Avogadro's number, approximately 6.022 x 10^23, is the number of atoms, molecules, or particles in one mole of a substance. This constant allows chemists to convert between the number of particles and the amount of substance in moles, which is essential for stoichiometric calculations.

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). For lead (Pb), the molar mass is approximately 207.2 g/mol. Knowing the molar mass is crucial for converting moles to grams when calculating the mass of a given number of atoms.

Mass Calculation from Atoms

To calculate the mass of a sample from the number of atoms, one first converts the number of atoms to moles using Avogadro's number. Then, the number of moles is multiplied by the molar mass of the element to find the mass in grams. This process is fundamental in quantitative chemistry.