Ammonium sulfate, (NH₄)₂SO₄, is used in fertilizers to provide nitrogen for the soil. (7.1, 7.2) c. How many moles of ammonium sulfate contain 7.4 x 10²⁵ atoms of N?

Verified step by step guidance

1. Determine the number of nitrogen atoms in one formula unit of ammonium sulfate, (NH_4)_2SO_4. Each ammonium ion, NH_4^+, contains one nitrogen atom, and there are two ammonium ions in the formula unit, so there are 2 nitrogen atoms per formula unit.
2. Use Avogadro's number, 6.022 x 10^23 atoms/mol, to convert the given number of nitrogen atoms to moles of nitrogen atoms.
3. Calculate the moles of ammonium sulfate by dividing the moles of nitrogen atoms by the number of nitrogen atoms per formula unit of ammonium sulfate.
4. Set up the equation: moles of ammonium sulfate = (moles of nitrogen atoms) / (2 nitrogen atoms per formula unit).
5. Solve the equation to find the moles of ammonium sulfate.

Key Concepts

Moles and Avogadro's Number

A mole is a unit in chemistry that represents 6.022 x 10²³ particles, which can be atoms, molecules, or ions. Avogadro's number is crucial for converting between the number of atoms and moles, allowing chemists to quantify substances in a manageable way.

Chemical Composition of Ammonium Sulfate

Ammonium sulfate, (NH₄)₂SO₄, consists of two ammonium ions (NH₄⁺) and one sulfate ion (SO₄²⁻). Each ammonium ion contains one nitrogen atom, meaning that one mole of ammonium sulfate contains two moles of nitrogen atoms, which is essential for calculating the number of moles based on nitrogen atoms.

Stoichiometry

Stoichiometry is the calculation of reactants and products in chemical reactions. It allows for the determination of the relationships between the quantities of substances involved, which is necessary for solving problems related to moles, such as finding how many moles of ammonium sulfate correspond to a given number of nitrogen atoms.