Question

Calculate the. number of moles of Cu. in 8.0×1021 atoms of Cu​

Answer 1

Answer:

8.0 × 10²¹ atoms contain 1.33 × 10⁻² moles.

Explanation:

The given problem will solve by using 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.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

Given data:

Number of atoms = 8.0 × 10²¹ atoms

Number of moles = ?

Solution:

One mole of Cu = 6.022 × 10²³ atoms

For 8.0 × 10²¹ atoms:

(1 mol / 6.022 × 10²³ atoms)×8.0 × 10²¹ atoms

1.33 × 10⁻² moles

So, 8.0 × 10²¹ atoms contain 1.33 × 10⁻² moles.