Calculate the number of molecules of NH3 if you have 4.86 moles.

Answer 1

Why not simply use DIMENSIONAL ANALYSIS? If you don't know what that is, or if you don't understand how to use it, you should learn. It's very important and very useful.

4.86 moles x 6.02x10²³ molecules / mole = ANSWER = 2.93x10²⁴ molecules

With dimensional analysis, you see how moles cancel, leaving you with molecules.

Answer 2

Use Avogadro's number .... 6.022 x 10^23.

This number can have be consider a count number in this situation.

There are 6.022 x 10^23 molecules for every mole.

If you have 4.00 moles of NH3, you have 4 times the molecules.

If you have an additional 0.86 moles of NH3, you have 0.86 times the molecules.

Then you could put it together.