4.515 x 10 24 atoms of Purellium Distinkamide is equal to ___ moles?

Answer 1

@Nate Y's answer is "right on" as far as explanation, but the wrong value was used for Avogadro's number.

Avogadro's number is 6.022x10²³ particles per mole. In out case it will be 6.022x10²³ atoms/mole.

Using dimensional analysis, we have....

4.515x10²⁴ atoms x 1 mole/6.022x10²³ atoms = 7.4975 moles = 7.498 moles of PD

Answer 2

"Purellium Distinkamide" is a silly joke name for a made-up compound. The idea of this question is that no matter what the substance we are talking about is - water (H₂O), hydrogen gas (H₂), or even "Purellium Distinkamide" - a mole is always the same number of molecules, 6.022 x 10²³. This is Avogadro's number and you have probably seen it around class a lot!

Since your number has 4 significant figures, use 6.022 x 10²³ for the number of molecules in a mole.

To find how many moles you have, take the given number 4.515 x 10²⁴, and divide it by 6.022 x 10²³.

The reason you do this is you are converting from molecules to moles by dimensional analysis.

4.515 x 10²⁴ molecules Purellium Distinkamide * 1 mole Purellium Distinkamide / (6.022 x 10²³ molecules Purellium Distinkamide)

Thanks for the question.