Question

How many aluminum atoms are there in 319 g of al2s3

Answer 1

Answer : The number of aluminium atoms are,
`25.65* 10^(23)`

Explanation : Given,

Mass of
`Al_2S_3` = 319 g

Molar mass of
`Al_2S_3` = 150 g/mole

First we have to calculate the moles of
`Al_2S_3`.

`\text{Moles of }Al_2S_3=\frac{\text{Mass of }Al_2S_3}{\text{Molar mass of }Al_2S_3}=(319g)/(150g/mole)=2.13moles`

Now we have to calculate the number of atoms of aluminium.

In
`Al_2S_3`, there are 2 atoms of aluminium and 3 atoms of sulfur.

As, 1 mole of
`Al_2S_3` contains
`2* 6.022* 10^(23)` number of aluminium atoms.

As, 2.13 mole of
`Al_2S_3` contains
`2.13* 2* 6.022* 10^(23)=25.65* 10^(23)` number of aluminium atoms.

Therefore, the number of aluminium atoms are,
`25.65* 10^(23)`

Answer 2

The number of aluminium atoms that are in 319 g of Al2S3 is calculated as follows

find the total moles of Al2s3

=moles = mass/molar = 319 g / 150 g/mol = 2.13 moles
since there are two atom of Al in Al2S3 the moles of Al = 2 x 2.13 = 4.26 moles

by use of Avogadro law constant 1 mole = 6.02 x10^23 atoms
what about 4.26 moles of Al

= 4.26 moles x( 6.02 x10^23) = 2.56 x10^ 24 atoms