Answer:
Step-by-step explanation:
To calculate the mass of a sample, we can use the concept of molar mass. The molar mass is the mass of one mole of a substance and is expressed in grams per mole (g/mol). To find the mass of a given number of moles, we can use the following formula:
Mass (g) = Number of moles (mol) × Molar mass (g/mol)
First, we need to find the molar mass of lithium nitride (Li3N). To do that, we add the molar masses of lithium (Li) and nitrogen (N).
Molar mass of Li = 6.941 g/mol
Molar mass of N = 14.007 g/mol
Molar mass of Li3N = (3 × Molar mass of Li) + Molar mass of N
Molar mass of Li3N = (3 × 6.941 g/mol) + 14.007 g/mol
Molar mass of Li3N = 20.823 g/mol + 14.007 g/mol
Molar mass of Li3N = 34.830 g/mol
Now that we have the molar mass of Li3N, we can calculate the mass of the 2.10 mol sample:
Mass (g) = 2.10 mol × 34.830 g/mol
Mass (g) = 73.173 g
The mass of a 2.10 mol sample of lithium nitride (Li3N) is approximately 73.173 grams.