Question

calculate the number of particles in each of the following a. 18 gram of O2 molecules b. 0.1 mole of Calcium atomic​

Answer 1

3.39 x 10²³ particles

6.02 x 10²²particles

Step-by-step explanation:

The problem here entails we find the number of particles in the given substances.

From the mole concept;

1 mole of a substance contains 6.02 x 10²³ particles

a. 18g of O₂;

We first find the number of moles of this substance first;

Number of moles =
`(mass)/(molar mass)`

Molar mass of O₂ = 2(16) = 32g/mol

Number of moles =
`(18)/(32)` = 0.56mole

So;

1 mole of a substance contains 6.02 x 10²³ particles

0.56 mole of O₂ will contain 0.56 x 6.02 x 10²³ particles

= 3.39 x 10²³ particles

b. 0.1mole of calcium atom:

1 mole of a substance contains 6.02 x 10²³ particles

0.1 mole of the substance will contain 0.1 x 6.02 x 10²³ particles

= 6.02 x 10²²particles