To determine the number of atoms in a given mass of a compound, you need to use the concept of molar mass and Avogadro's number.
First, calculate the molar mass of K2PtCl6:
- Potassium (K) has an atomic mass of approximately 39.10 g/mol.
- Platinum (Pt) has an atomic mass of approximately 195.08 g/mol.
- Chlorine (Cl) has an atomic mass of approximately 35.45 g/mol.
The compound K2PtCl6 consists of two potassium atoms, one platinum atom, and six chlorine atoms. Therefore, the molar mass is:
(2 * 39.10 g/mol) + (1 * 195.08 g/mol) + (6 * 35.45 g/mol) = 485.26 g/mol
Now, you can use this molar mass to convert the given mass (0.7569 g) into moles:
moles = mass / molar mass moles = 0.7569 g / 485.26 g/mol ≈ 0.00156 mol
Finally, use Avogadro's number to convert moles to the number of atoms:
number of atoms = moles * Avogadro's number number of atoms = 0.00156 mol * 6.022 × 10^23 atoms/mol ≈ 9.39 × 10^20 atoms
Therefore, there are approximately 9.39 × 10^20 atoms in 0.7569 g of K2PtCl6.