Ammonium sulfate, (NH₄)₂SO₄, is used in fertilizers to provide nitrogen for the soil. (7.1, 7.2)a. How many formula units are in 0.200 mole of ammonium sulfate?

If a sample of sodium chloride, NaCl, contains 73.1 kg, what is its number of formula units?

Calculate the number of oxygen atoms found in 783.9 g NiCl₂ • 6 H₂O.

If the density of water is 1.00 g/mL at 25°C, calculate the number of water molecules found in 1.50 x 10³ µL of water.

A cylindrical copper wire is used for the fences around a house. The copper wire has a diameter of 0.0750 in. How many copper atoms are found in 5.160 cm piece? The density of copper is 8.96 g/cm³. (V = π • r² • h)