Mass Of Sulfur In Copper Sulfide

Calculating the Mass of Sulfur in Copper Sulfide

Copper sulfide (Cu₂S) is a naturally occurring mineral, and understanding its composition, particularly the mass of sulfur within it, is crucial in various fields like metallurgy, chemistry, and geochemistry. This article will guide you through the process of calculating the mass of sulfur present in a given mass of copper sulfide, using fundamental principles of stoichiometry. This involves understanding molar mass, mole ratios, and applying the relevant chemical formula.

Understanding the Chemical Formula (Cu₂S)

The chemical formula Cu₂S tells us that one molecule of copper sulfide contains two copper (Cu) atoms and one sulfur (S) atom. This ratio is fundamental to our calculations. We'll use the molar masses of copper and sulfur to convert between mass and moles.

Calculating Molar Mass

Before we can determine the sulfur mass, we need the molar masses of copper and sulfur. These are readily available on a periodic table:

• Copper (Cu): Approximately 63.55 g/mol
• Sulfur (S): Approximately 32.07 g/mol

The molar mass of copper sulfide (Cu₂S) is calculated as follows:

(2 * molar mass of Cu) + (1 * molar mass of S) = (2 * 63.55 g/mol) + (1 * 32.07 g/mol) = 159.17 g/mol

This means one mole of Cu₂S weighs 159.17 grams.

Determining the Mass Percentage of Sulfur

To determine the mass percentage of sulfur in Cu₂S, we use the following formula:

(Mass of Sulfur in one mole of Cu₂S / Molar mass of Cu₂S) * 100%

= (32.07 g/mol / 159.17 g/mol) * 100% ≈ 20.15%

This indicates that approximately 20.15% of the mass of copper sulfide is sulfur.

Calculating the Mass of Sulfur in a Given Mass of Cu₂S

Let's say we have a 100-gram sample of copper sulfide (Cu₂S). To find the mass of sulfur in this sample, we can use the mass percentage we calculated:

Mass of sulfur = (Mass percentage of sulfur / 100%) * Mass of Cu₂S sample

Mass of sulfur = (20.15% / 100%) * 100 g ≈ 20.15 g

Therefore, there are approximately 20.15 grams of sulfur in a 100-gram sample of copper sulfide.

Example Problem and Solution

Problem: A geologist has a 50 gram sample of chalcocite (Cu₂S). What is the mass of sulfur in this sample?

Solution:

1. Find the mass percentage of sulfur: As calculated above, the mass percentage of sulfur in Cu₂S is approximately 20.15%.
2. Calculate the mass of sulfur: (20.15%/100%) * 50g = 10.075g

Therefore, the mass of sulfur in the 50-gram sample of chalcocite is approximately 10.075 grams.

Conclusion

Calculating the mass of sulfur in copper sulfide is a straightforward process involving molar masses and mass percentages. This fundamental calculation is crucial in various scientific and industrial applications, highlighting the importance of understanding stoichiometry and chemical formulas. Remember to always double-check your calculations and ensure you are using the correct molar masses from a reliable source like a periodic table. This method can be easily adapted to determine the mass of any component in any chemical compound.