A sample of potassium sulfide (K2S) is known to have 0.199 moles. If each mole of K2S weights 110.3 g, what is the mass of the sample?

Question

The mole is a unit of measurement used to describe the amount of a chemical substance. The mass of a chemical substance can be calculated by multiplying the number of moles by the mass of one mole. A sample of potassium sulfide (K₂S) is known to have 0.199 moles. If each mole of K₂S weights 110.3 g, what is the mass of the sample? Round your answer appropriately.

mass=

 ______g

Answer 1

Dimensional analysis:

0.199 moles x 110.3 g/mole = 21.9 g (to 3 significant figures)

The problem tells you exactly how to do this problem. It says "The mass can be calculated by multiplying the number of moles by the mass of one mole. The number of moles is 0.199 and the mass of one mole is 110.3. Didn't you at least try to do what the problem said to do? Just curious.