Question

Question #4b22d

Answer 1

`4.9\times 10^{23}` oxygen atoms

Explanation:

The molar mass of `"AlPO"_4` is `26.98 + 30.97 + 4\cdot 16.00 = 121.95 \frac{\text{g}}{\text{mol}}`.

This comes from the periodic table.

Now, we convert `"25 g"` `"AlPO"_4` to moles `"AlPO"_4`:

`25\text{ g }\cdot\frac{\text{mol}}{121.95\text{ g}} = "0.205 mol AlPO"_4`

We can convert this to formula units of `"AlPO"_4` using Avogadro's constant, `6.02\times 10^{23}`.

`"0.205 moles" \cdot 6.02\times 10^{23}\text{ mol}^{-1} = 1.23\times 10^{23}` `"formula units AlPO"_4`

Since there are 4 oxygen atoms per formula unit of `"AlPO"_4`, we multiply this by 4 to get our answer:

`4\cdot 1.23\times 10^{23} = 4.9\times 10^{23}` oxygen atoms.