Question

What is the molarity of potassium ions in 80.0 mL of 2.00 M potassium sulfide (K2S)?

Answer 1

Answer:

0.32 moles of K+ ions.

Explanation:

The question is about the morality of Potassium Ions.

The formula of potassium sulfate = K2​S.

Molarity = No of . Moles / Volume

No of Moles = Molarity × Volume

= 2 × 80/1000

= 0.16 moles

Hence the number of moles of K2S would be 0.16. Now when this is broken down to potassium ions, we would get

1 mol of K2​S​ will yeild 2 moles of K+ ions.

0.16 moles of K2​S will give 0.32 moles of K+ ions.

Answer 2

The molarity of potassium ions in 80.0 mL of 2.00 M potassium sulfide is 25 M

Given:

Volume = 80 mL

Number of moles = 20 M

Molar mass of K₂S = (39 × 2) + 32 = 220 g

Explanation:

The molarity is given by the formula:

Molarity = (Number of moles)/(Volume in liter)

On substituting the values, we get,

Molarity = (20 × 1000)/80

∴ Molarity = 25 M