To determine how many moles of barium chloride (BaCl2) are in 87.3 grams of the compound, we need to follow these steps:
1. Calculate the molecular weight of BaCl2:
- The atomic weight of barium (Ba) is 137.327 g/mol.
- The atomic weight of chlorine (Cl) is 35.453 g/mol. Since there are two chlorine atoms in barium chloride, we multiply by 2.
Therefore, the molecular weight of BaCl2 is calculated as:
[tex]\[
\text{Molecular weight of BaCl2} = \text{Atomic weight of Ba} + 2 \times \text{Atomic weight of Cl}
\][/tex]
[tex]\[
\text{Molecular weight of BaCl2} = 137.327 + 2 \times 35.453
\][/tex]
[tex]\[
\text{Molecular weight of BaCl2} = 137.327 + 70.906
\][/tex]
[tex]\[
\text{Molecular weight of BaCl2} = 208.233 \text{ g/mol}
\][/tex]
2. Use the molecular weight to find the number of moles:
The number of moles is found using the formula:
[tex]\[
\text{Number of moles} = \frac{\text{Mass of the substance (g)}}{\text{Molecular weight (g/mol)}}
\][/tex]
Substituting the given mass and the calculated molecular weight:
[tex]\[
\text{Number of moles of BaCl2} = \frac{87.3 \text{ g}}{208.233 \text{ g/mol}}
\][/tex]
3. Perform the division:
[tex]\[
\text{Number of moles of BaCl2} = 0.4192419069023642 \text{ mol}
\][/tex]
So, there are approximately 0.419 moles of barium chloride (BaCl2) in 87.3 grams of the compound.
