1. Calculate the moles of C6H6:

* Find the molar mass of C6H6:

* Carbon (C) has a molar mass of 12.01 g/mol.

* Hydrogen (H) has a molar mass of 1.01 g/mol.

* Molar mass of C6H6 = (6 * 12.01 g/mol) + (6 * 1.01 g/mol) = 78.12 g/mol

* Divide the mass of C6H6 by its molar mass:

* Moles of C6H6 = 15.0 g / 78.12 g/mol = 0.192 mol

2. Determine the moles of NH3:

* Since we want the same number of molecules, the number of moles of NH3 will be the same as the number of moles of C6H6.

* Therefore, moles of NH3 = 0.192 mol

3. Calculate the mass of NH3:

* Find the molar mass of NH3:

* Nitrogen (N) has a molar mass of 14.01 g/mol.

* Hydrogen (H) has a molar mass of 1.01 g/mol.

* Molar mass of NH3 = 14.01 g/mol + (3 * 1.01 g/mol) = 17.04 g/mol

* Multiply the moles of NH3 by its molar mass:

* Mass of NH3 = 0.192 mol * 17.04 g/mol = 3.27 g

Therefore, 3.27 grams of NH3 will have the same number of molecules as 15.0 grams of C6H6.