Final answer:
To calculate the percent composition of potassium in potassium sulfide, divide the mass of potassium by the molar mass of potassium sulfide and multiply by 100%. The answer is approximately 55.84%.
Step-by-step explanation:
To calculate the percent composition of potassium in potassium sulfide, we need to determine the molar mass of potassium sulfide and the molar mass of potassium. The molar mass of potassium sulfide is 70.09 g/mol, and the molar mass of potassium is 39.10 g/mol. The percent composition of potassium in potassium sulfide can be calculated using the formula:
(mass of potassium / molar mass of potassium sulfide) x 100%
Let's calculate it:
(39.10 g / 70.09 g/mol) x 100% = 55.84%
Therefore, the percent composition of potassium in potassium sulfide is approximately 55.84%.