Final answer:
The number of moles in a 15.820 g sample of chlorine gas (Cl₂), divide the mass of the chlorine by its molar mass of 70.90 g/mol, which yields approximately 0.223 moles.
Step-by-step explanation:
To determine how many moles are there in a 15.820 g sample of chlorine gas (Cl₂), we must use the molar mass of chlorine gas and the standard conversion between grams and moles. The molar mass of chlorine gas is 70.90 g/mol, which is the sum of the masses of two chlorine atoms. Avogadro's number is 6.022 × 10²³ molecules/mol and is used when converting moles to molecules.
Here's the calculation to find the number of moles of chlorine gas in a 15.820 g sample:
Number of moles = Mass of sample (g) / Molar mass (g/mol)
Number of moles = 15.820 g / 70.90 g/mol
Number of moles = approximately 0.223 moles of Cl₂