Final answer:
To calculate the quantity in moles of NaI in 82.0 grams, the mass of NaI is divided by its molar mass (149.89 g/mol), resulting in 0.547 moles of NaI.
Step-by-step explanation:
The quantity in moles of NaI in 82.0 grams can be calculated using the molar mass of NaI. To find the number of moles, you divide the mass of the substance by its molar mass. The molar mass of NaI (sodium iodide) is the sum of the atomic masses of sodium (Na) and iodine (I), which are approximately 22.99 g/mol and 126.90 g/mol, respectively, giving us a molar mass of approximately 149.89 g/mol for NaI.
Using the formula:
Number of moles = Mass of substance (g) / Molar mass (g/mol)
We get:
Number of moles of NaI = 82.0 g / 149.89 g/mol = 0.547 moles
Therefore, there are 0.547 moles of NaI in 82.0 grams of NaI. This is a straightforward stoichiometry calculation that is common in chemistry courses.