The molar mass of copper chloride, CuCl2 is 134gmol−1
is 134gmol−1 . How many formula units of CuCl2
are present in 17.6g
of CuCl2
?

To find out how many formula units of copper(II) chloride (CuCl₂) are present in 17.6 g of the compound, we can follow these steps:

### Step 1: Calculate the number of moles of CuCl₂

The number of moles of a substance can be calculated using the formula:

\[
\text{Number of moles} = \frac{\text{mass of substance (g)}}{\text{molar mass (g/mol)}}
\]

For CuCl₂:

- **Mass of CuCl₂** = 17.6 g
- **Molar mass of CuCl₂** = 134 g/mol

Substituting these values into the formula:

\[
\text{Number of moles of CuCl₂} = \frac{17.6 \, \text{g}}{134 \, \text{g/mol}} \approx 0.1313 \, \text{mol}
\]

### Step 2: Calculate the number of formula units

To find the number of formula units, we can use Avogadro's number, which states that one mole of any substance contains approximately \(6.022 \times 10^{23}\) formula units.

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

Substituting in our values:

\[
\text{Number of formula units} = 0.1313 \, \text{mol} \times 6.022 \times 10^{23} \, \text{units/mol}
\]

Calculating this gives:

\[
\text{Number of formula units} \approx 7.91 \times 10^{22} \, \text{units}
\]

### Final Answer

Therefore, in 17.6 g of CuCl₂, there are approximately \(7.91 \times 10^{22}\) formula units of CuCl₂.