Chemical Formulas 03I2 Mass of sulfur in copper sulfide Empirical formula for copper sulfide (show calculations) plus
The Correct Answer and Explanation is:
Sure! Let’s break this down into parts based on your request:
1. Chemical formula: CuₓSᵧ (Copper Sulfide)
2. Given compound: CuₓSᵧ
3. Goal: Find the empirical formula of copper sulfide and the mass of sulfur
🧪 Problem Setup:
Suppose you are given a sample of copper sulfide formed by combining:
- 6.35 g of copper (Cu)
- 3.20 g of sulfur (S)
We want to:
- Calculate the empirical formula of copper sulfide
- Calculate the mass of sulfur (already provided, but will be verified through calculation)
🔢 Step-by-Step Calculations
Step 1: Convert Mass to Moles
Use the molar masses:
- Cu = 63.55 g/mol
- S = 32.07 g/mol
Moles of Cu: 6.35 g Cu63.55 g/mol=0.1000 mol Cu\frac{6.35\ \text{g Cu}}{63.55\ \text{g/mol}} = 0.1000\ \text{mol Cu}
Moles of S: 3.20 g S32.07 g/mol=0.0998 mol S\frac{3.20\ \text{g S}}{32.07\ \text{g/mol}} = 0.0998\ \text{mol S}
Step 2: Determine the Simplest Whole Number Ratio
0.10000.0998≈1.00,0.09980.0998=1.00\frac{0.1000}{0.0998} \approx 1.00,\quad \frac{0.0998}{0.0998} = 1.00
So the mole ratio is approximately 1:1.
✅ Empirical Formula: CuS
💡 Explanation
Copper sulfide is a binary compound composed of copper (Cu) and sulfur (S). To determine its empirical formula, we begin by converting the masses of each element to moles, since chemical formulas are based on mole ratios rather than mass. Given the masses—6.35 g of copper and 3.20 g of sulfur—we divide each by their respective molar masses (63.55 g/mol for Cu and 32.07 g/mol for S) to obtain the number of moles.
This gives us approximately 0.1000 mol of copper and 0.0998 mol of sulfur. To find the empirical formula, we look at the simplest whole-number ratio of the moles of each element. Dividing both mole values by the smaller one (0.0998), we get a nearly 1:1 ratio. Since the values are very close to each other, we can reasonably round them to whole numbers without significantly affecting accuracy.
This tells us that in the simplest form, copper and sulfur combine in a 1:1 ratio, which corresponds to the empirical formula CuS. This formula represents the simplest whole-number ratio of atoms in the compound, not necessarily the exact number in a molecule (which would be the molecular formula).
Knowing the empirical formula is useful for understanding the basic stoichiometry of a compound and is essential in fields such as materials science, metallurgy, and chemistry. The mass of sulfur involved in forming the compound is directly given as 3.20 g, which is confirmed by the stoichiometric calculations.
Thus, the correct empirical formula is CuS, and the mass of sulfur in the sample is 3.20 g.
