Answer: To find the number of moles of chloride ions in aluminum chloride, we need to use the molar mass of aluminum chloride and the given mass of the compound.
The molar mass of aluminum chloride (AlCl3) can be calculated by adding the atomic masses of aluminum (Al) and three chlorine (Cl) atoms. The atomic mass of Al is 26.98 g/mol, and the atomic mass of Cl is 35.45 g/mol.
So, the molar mass of AlCl3 is:
(1 × 26.98 g/mol) + (3 × 35.45 g/mol) = 133.34 g/mol.
Given that the mass of aluminum chloride is 0.2540 g, we can now calculate the number of moles of aluminum chloride using the formula:
moles = mass / molar mass.
moles = 0.2540 g / 133.34 g/mol.
Calculating this, we find that there are approximately 0.00191 moles of aluminum chloride.
Since aluminum chloride has a 1:3 ratio of aluminum ions to chloride ions, there will be three times as many moles of chloride ions as there are moles of aluminum chloride.
Therefore, the number of moles of chloride ions is:
3 × 0.00191 moles = 0.00573 moles.
So, there are approximately 0.00573 moles of chloride ions in 0.2540 g of aluminum chloride.