Here's how to calculate the number of molecules in 3 moles of ammonia (NH3):

1. Avogadro's Number:

* Avogadro's number tells us the number of particles (atoms, molecules, etc.) in one mole of a substance. It's approximately 6.022 x 10^23 particles/mole.

2. Calculation:

* Step 1: Multiply the number of moles by Avogadro's number:

3 moles NH3 * (6.022 x 10^23 molecules/mole) = 1.8066 x 10^24 molecules

Answer: There are approximately 1.8066 x 10^24 molecules in 3 moles of ammonia (NH3).