Question

What is the mass of 5.05×1021 platinum atoms?

Answer 1

Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles. We calculate as follows:

5.05×10^21 atoms Pt ( 1 mol / 6.022 x 10^23 atoms ) ( 195.084 g / 1 mol ) = 1.64 g Pt

Answer 2

Answer: 1.6 gram

Step-by-step explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number
`6.023* 10^(23)` of particles.

To calculate the moles, we use the equation:

`\text{Number of moles}=\frac{\text{Given atoms}}{\text {Avogadro's Number}}`

`\text{Number of moles of water}=(5.05* 10^(21))/(6.023* 10^(23))=8.4* 10^(-3)moles`

1 mole of Platinum
`Pt` weighs 195 g

`8.4* 10^(-3)moles` of Platinum
`Pt` weigh =
`(195)/(1)* 8.4* 10^(-3)=1.6g`

Thus mass of
`5.05* 10^(21)` platinum atoms is 1.6 gram.