Question

How many moles of atoms does a 200. g bar of silver contain?

		1.85 moles
		1.02 moles
		1.12 x 1024 moles
		3.32 moles
		3.32 x 10-22 moles How do I figure out number of moles?

Answer 1

The atomic mass of silver (Ag) is 107.87 g/mol.

Given mass of silver (Ag) = 200 g

We know that number of moles of any substance is determined as follows:

Moles =

mass of the substance / molar or atomic mass of substance.

= 200 g / 107.87 g / mol

= 1.85 mol of atoms Ag.

So, answer:

Option 1) 1.85 moles. (of Ag)

Extra information:

1 mole of atoms = 6.023 × 10^23 atoms (Avogadro's number).

Therefore 1.85 moles = 1.85 × 6.023 × 10^23 atoms.

= 1.12 × 10^24 atoms of Ag.