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1) In the laboratory you dissolve 19.8 g of manganese(II) iodide in a volumetric

ID: 570340 • Letter: 1

Question

1) In the laboratory you dissolve 19.8 g of manganese(II) iodide in a volumetric flask and add water to a total volume of 125 mL.

What is the molarity of the solution?____ M.

What is the concentration of the manganese(II) cation?____ M.

What is the concentration of the iodide anion?____ M.

2)In the laboratory you dissolve 23.3 g of silver fluoride in a volumetric flask and add water to a total volume of 500 mL.

What is the molarity of the solution?____ M.

What is the concentration of the silver cation?____ M.

What is the concentration of the fluoride anion?____ M.

3)In the laboratory you dissolve 14.8 g of potassium acetate in a volumetric flask and add water to a total volume of 500 mL.

What is the molarity of the solution?____ M.

What is the concentration of the potassium cation?____ M.

What is the concentration of the acetate anion?____ M.

Explanation / Answer

1)

mass of MnI2 = 19.8 g

moles of MnI2 = 19.8 / 308.75 = 0.0641 mol

volume = 125 mL = 0.125 L

Molarity = moles / volume

           = 0.0641 / 0.125

Moalrity = 0.513 M

What is the concentration of the manganese(II) cation = 0.513 M

What is the concentration of the iodide anion = 1.03 M

2)

moles of AgF = 23.3 / 126.87 = 0.184

Molarity = 0.184 / 0.5 = 0.367 M

Moalrity = 0.367 M

concentration of Ag+ = 0.367 M

concentration of F- = 0.367 M