Question

10 points!! Please answer only if you know the correct answer I’m already failing the class :/

How many moles are represented by 9.34 x 1021 sodium atoms?

a . 1.25 x 10^-2 moles

b. 1.55 x 10^-3 moles

c. 1.55 x 10^-2 moles

d. 1.55 moles

Answer 1

c) 1.55 ×10⁻² moles

Step-by-step explanation:

Given data:

Number of moles of sodium = ?

Number of atoms = 9.34 ×10²¹ atoms

Solution:

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

Moles of sodium atoms:

1 mole contain 6.022× 10²³ atoms

9.34 ×10²¹ atoms × 1 mol / 6.022× 10²³ atoms

1.55 ×10⁻² moles