Avogadro's Number Chemistry Example 5

Follow the full solution, then compare it with the other examples linked below.

Example 5

medium
How many chloride ions are in 0.2000.200 mol of CaCl2\text{CaCl}_2?

Solution

  1. 1
    Each formula unit of CaCl2\text{CaCl}_2 contains 2 chloride ions, so first find formula units: 0.200×6.022×1023=1.204×10230.200 \times 6.022 \times 10^{23} = 1.204 \times 10^{23}.
  2. 2
    Multiply by 2 chloride ions per formula unit: 2×1.204×1023=2.41×10232 \times 1.204 \times 10^{23} = 2.41 \times 10^{23} chloride ions.

Answer

2.41×1023 chloride ions2.41 \times 10^{23}\text{ chloride ions}
Avogadro's number converts moles into particles. When the formula contains more than one of an atom or ion, multiply by that subscript after converting to particles.

About Avogadro's Number

The defined number of particles in exactly one mole of any substance: 6.022×10236.022 \times 10^{23}.

Learn more about Avogadro's Number →

More Avogadro's Number Examples

Example 1 easy

How many molecules are in [formula] mol of [formula]?

Example 2 medium

How many individual oxygen atoms are in [formula] mol of [formula]?

Example 3 medium

How many molecules are in 2.5 moles of water ([formula])? How many individual atoms is that?

Example 4 easy

How many atoms are in [formula] mol of iron (Fe)?

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Related Concepts

MoleMolar Mass