Question

A lead pipe weighs 25 lbs.How many atoms of lead are in the pipe?

a) 6.022 x 10^23 atoms
b) 3.011 x 10^23 atoms
c) 1.204 x 10^24 atoms
d) 3.3 x 10ˆ25 atoms

Answer 1

To find the number of lead atoms in a 25 lb lead pipe, convert the weight to grams, compute moles based on the atomic mass of lead, and then multiply by Avogadro's number, resulting in approximately 3.3 × 10¹⁵ atoms.

Step-by-step explanation:

To determine how many atoms of lead are in a 25 lb pipe, we first need to find the number of moles of lead the pipe contains and then use Avogadro's number to convert moles to atoms. The atomic mass of lead (Pb) is approximately 207.2 g/mol. To find the mass in grams, we convert pounds to grams (1 lb is approximately 453.59237 g).

So, the mass of the pipe in grams is:

25 lb × 453.59237 g/lb = 11339.80925 g

Now, we calculate the number of moles of lead:

Moles of lead = mass of lead / atomic mass of lead = 11339.80925 g / 207.2 g/mol

This calculation yields approximately 54.765 moles of lead.

To find the number of atoms, we use Avogadro's number (6.022 × 1023 atoms/mol):

Number of atoms = 54.765 moles × 6.022 × 1023 atoms/mol

The calculation gives us approximately 3.3 × 1025 atoms of lead in the pipe.