Question

How many NH4+ ions are in 550 mg of (NH4)3PO4?

My professor usually goes over our in class assignment in class and then assigns us a weekly assignment to finish for homework with the problems being similar to what she has explained. We didn't go over one like this and I don't know how to approach it.

Answer 1

7.53 × 10²¹ NH₄⁺ ions

Step-by-step explanation:

Step 1: Given data

Mass of (NH₄)₃PO₄: 550 mg

Step 2: Convert 550 mg to grams

We will use the conversion factor 1 g = 1000 mg.

550 mg × (1 g/1000 mg) = 0.550 g

Step 3: Calculate the moles corresponding to 0.550 g of (NH₄)₃PO₄

The molar mass of (NH₄)₃PO₄ is 132.06 g/mol.

0.550 g × (1 mol/132.06 g) = 4.16 × 10⁻³ mol

Step 4: Calculate the moles of NH₄⁺ in 4.16 × 10⁻³ moles of (NH₄)₃PO₄

The molar ratio of (NH₄)₃PO₄ to NH₄⁺ is 1:3. The moles of NH₄⁺ are 3/1 × 4.16 × 10⁻³ mol = 0.0125 mol

Step 5: Calculate the number of ions in 0.0125 moles of NH₄⁺

We will use Avogadro's number: there are 6.02 × 10²³ NH₄⁺ ions in 1 mole of ions of NH₄⁺.

0.0125 mol × (6.02 × 10²³ ions/1 mol) = 7.53 × 10²¹ ions