What mass of antimony is contained in 106g of stibnite, Sb2S3?
The correct answer and explanation is:
To find the mass of antimony (Sb) contained in 106 g of stibnite (Sb₂S₃), follow these steps:
Step 1: Calculate the molar mass of stibnite (Sb₂S₃)
- Atomic mass of antimony (Sb) = 121.76 g/mol
- Atomic mass of sulfur (S) = 32.06 g/mol
Molar mass of Sb₂S₃ = (2 × 121.76) + (3 × 32.06)
= 243.52 + 96.18
= 339.70 g/mol
Step 2: Determine the mass fraction of antimony in stibnite
Mass of Sb in one mole of Sb₂S₃ = 2 × 121.76 = 243.52 g
Mass fraction of Sb = 243.52 g / 339.70 g = 0.717
Step 3: Calculate the mass of antimony in 106 g of stibnite
Mass of Sb = Mass fraction of Sb × mass of stibnite
= 0.717 × 106 g
= 75.99 g
Final answer:
The mass of antimony contained in 106 g of stibnite is approximately 76.0 g.
Explanation:
Stibnite is a mineral composed of antimony and sulfur with the formula Sb₂S₃. To find how much antimony is in a given amount of stibnite, it is important to understand the proportion of antimony in the compound by mass. First, calculate the total molar mass of Sb₂S₃ by adding the molar masses of its elements, considering their number of atoms. The molar mass reflects how much one mole of the compound weighs.
Next, determine what fraction of that molar mass is due to antimony alone. Since there are two antimony atoms, multiply the atomic mass of Sb by two and divide by the total molar mass of stibnite. This fraction tells us the percentage by mass of antimony in the compound.
Finally, multiply the given mass of stibnite by this fraction to find the actual mass of antimony in that sample. This method is a standard approach in chemistry for calculating the mass of a component within a compound, using the concept of molar masses and mass fractions.