Question

A sample of Vitamin C is known to contain 2.58×10^24 oxygen atoms. How many moles of O2 are present in the sample.
Give the answer with appropriate steps.

Answer 1

Given:

The number of oxygen atoms present in the sample = 2.58 X 10²⁴

To Find:

The number of moles of O₂

Solution:

We know that 1 mole of any substance contains exactly 6.022 X 10²³ number of atoms or molecules.

This number is often represented as Na and called the Avogadro Number.

Using the unitary method, we can conclude that

1 atom/ molecule is present in  $\frac{1}{6.022X10^2^3}$  moles.

So, 2.58 X 10²⁴ atoms are present in  $\frac{2.58 X 10^2^4}{6.022X10^2^3}$

= 0.428 X 10

= 4.28 moles.

These are the number of moles of oxygen atoms.

The number of moles of O₂ = Moles of Oxygen atoms / 2

= 4.28 / 2

= 2.14

Hence, 2.14 moles of O₂ are present in the sample.

Answer 2

2.58×10 to the power 24×6.022×10 the power 23

0.428×10

4.28.

the numbers of moles of O2=4.28/2=2.14moles