Question

Convert 0.20 mol of boron into grams of boron. How many atoms are present?

Answer 1

The mass of boron is 0.2*10.81=2.162 g. And the atoms number is related with the mole number. So the atom number is 0.2*6.02*10^23 = 1.204*10^23.

Answer 2

Step-by-step explanation:

As molar mass of boron is 10.8 g/mol and it is given that its number of moles is 0.20 mol.

Therefore, calculate its mass as follows.

No. of moles =
`\frac{mass}{\text{molar mass}}`

0.20 mol =
`(mass)/(10.8 g/mol)`

= 2.16 g

And, according to the mole concept there are
`6.022 * 10^(23) atoms` present in 1 mole of a substance.

Mathematically, 1 mole =
`6.022 * 10^(23)` atoms or molecules

Therefore, calculate the number of atoms present in 0.20 mol of boron as follows.

`0.20 * 6.022 * 10^(23)}atoms /mol`

=
`1.204 * 10^(23)` atoms

Thus, we can conclude that mass of boron is 2.16 g and it contains
`1.204 * 10^(23)` atoms.