How many moles are equal to 2.4×10^23 formula units of sodium chloride?

To calculate the number of moles from the number of formula units, you'll need to use Avogadro's number, which is \(6.022 \times 10^{23}\) formula units per mole. This conversion factor tells us how many formula units are in one mole of any substance.

Here's how you can calculate the moles from the given number of formula units:

\[ \text{Number of moles} = \frac{\text{Number of formula units}}{\text{Avogadro's number}} \]

Now, plug in the given values:

\[ \text{Number of moles} = \frac{2.4 \times 10^{23}}{6.022 \times 10^{23}} \]

When you do the division, you get:

\[ \text{Number of moles} \approx 0.398 \]

So, there are approximately 0.398 moles in \(2.4 \times 10^{23}\) formula units of sodium chloride.

Extra: The concept of moles is fundamental to chemistry. A mole is a unit that measures the amount of substance. Avogadro's number is a constant that represents the number of particles, like atoms or molecules, in one mole of a substance. Essentially, it's similar to a dozen, which always means 12, except a mole always equals \(6.022 \times 10^{23}\) particles.

In the context of sodium chloride, or table salt, a formula unit refers to the smallest electrically neutral collection of ions. One formula unit of sodium chloride consists of one sodium ion (Na⁺) and one chloride ion (Cl⁻). This concept is crucial when discussing ionic compounds as they are made up of a lattice of ions rather than discrete molecules, often making the term "formula unit" more appropriate than "molecule". When chemists or students work with substances in the lab, measuring them out by moles can be very practical because it's often easier to weigh out grams of a substance rather than counting out individual atoms or molecules.