Question

Determine the number of Au atoms found in 5.18 grams of gold.

Answer 1

Answer:

1.58× 10²² atoms of Au

Explanation:

Given data:

Mass of gold = 5.18 g

Number of atoms of gold = ?

Solution:

First of all we will calculate the number of moles of gold.

Number of moles = mass/molar mass

Number of moles = 5.18 g/196.96 g/mol

Number of moles = 0.0263 mol

Number of atoms:

Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms of Au

0.0263 mol × 6.022 × 10²³ atoms of Au / 1mol

0.158× 10²³ atoms of Au

1.58× 10²² atoms of Au