Question

How many moles of pcl3 contain 3.68 × 1025 chlorine atoms?

Answer 1

Answer: The moles of
`PCl_3` that contain given number of chlorine atoms is 20.4 moles

Step-by-step explanation:

We are given:

Number of atoms of chlorine =
`3.68* 10^(25)`

A chemical compound having chemical formula
`PCl_3`

In 1 mole of phosphorus trichloride, 1 mole of phosphorus atom and 3 moles of chlorine atoms are present.

According to mole concept:

`6.022* 10^(23)` number of molecules occupy 1 mole of a compound.

So,
`3* 6.022* 10^(23)=1.8066* 10^(24)` number of chlorine atoms occupy 1 mole of phosphorus trichloride

Then,
`3.68* 10^(25)` number of chlorine atoms will occupy =
`(1)/(1.8066* 10^(24))* 3.68* 10^(25)=20.4moles` of phosphorus trichloride

Hence, the moles of
`PCl_3` that contain given number of chlorine atoms is 20.4 moles

Answer 2

To answer the question above, we take note first that every mole of PCl₃ contains 3 atoms of Cl. First, we divide the given number by 3.
3.68 x 10²⁵ / 3 = 1.227 x 10²⁵
Then, we divide the answer by the Avogadro's number which is equal to 6.022 x 10²³. That is,
1.227 x 10²⁵ / (6.022 x 10²³) = 20.37
Thus, there are 20.37 mol of PCl₃.