To determine the mass of potassium (K) that reacts with 6.41 grams of sulfur (S) to form 10.32 grams of potassium sulfide (K₂S), we can use the law of conservation of mass. This law states that the total mass of the reactants in a chemical reaction must equal the total mass of the products.
### Step-by-Step Solution:
1. Identify the given masses:
- Mass of sulfur (S) = 6.41 grams
- Mass of potassium sulfide (K₂S) = 10.32 grams
2. Apply the law of conservation of mass:
According to the law, the total mass of the reactants (potassium and sulfur) equals the mass of the product (potassium sulfide). Therefore, we can express this as:
[tex]\[\text{Mass of K} + \text{Mass of S} = \text{Mass of K₂S}\][/tex]
3. Rearrange the equation to solve for the mass of potassium (K):
[tex]\[\text{Mass of K} = \text{Mass of K₂S} - \text{Mass of S}\][/tex]
4. Substitute the known values:
[tex]\[\text{Mass of K} = 10.32 \, \text{grams} - 6.41 \, \text{grams}\][/tex]
5. Calculate the mass of potassium (K):
[tex]\[\text{Mass of K} = 3.91 \, \text{grams}\][/tex]
Therefore, the mass of potassium that reacts with 6.41 grams of sulfur to form 10.32 grams of potassium sulfide is 3.91 grams.
Given the provided multiple choice options, the correct answer is:
[tex]\[ \boxed{3.91 \, \text{grams}} \][/tex]
