Calculate the number of moles and the mass of the solute in each of the following solutions:
(a) 325 ml of 8.23 x 10-5 m kl, a source of iodine in the diet
(b) 75.0 ml of 22 x 10-5 m h2so4, a sample of acid rain
(c) 0.2500 l of 0.1135 m k2cro4 and analytical reagent used in iron assays
(d)10.5 l of 3.716 m (nh4)2so4, a liquid fertilizer

For a: The number of moles of KI are and mass is

For b: The number of moles of sulfuric acid are and mass is

For c: The number of moles of potassium chromate are and mass is 5.51 g.

For d: The number of moles of ammonium sulfate are 39.018 moles and mass is 5155.84 grams.

Explanation:

To calculate the molarity of solution, we use the equation:

   .....(1)

To calculate the number of moles of a substance, we use the equation:

    .....(2)

Molarity of KI =

Volume of solution = 325 mL = 0.325 L     (Conversion factor: 1 L = 1000 mL)

Putting values in equation 1, we get:

Now, using equation 2, we get:

Moles of KI =

Molar mass of KI = 166 g/mol

Putting values in equation 2, we get:

Hence, the number of moles of KI are and mass is

Molarity of sulfuric acid =

Volume of solution = 75 mL = 0.075 L

Putting values in equation 1, we get:

Now, using equation 2, we get:

Moles of sulfuric acid =

Molar mass of sulfuric acid = 98 g/mol

Putting values in equation 2, we get:

Hence, the number of moles of sulfuric acid are and mass is

Molarity of potassium chromate =

Volume of solution = 0.250 L

Putting values in equation 1, we get:

Now, using equation 2, we get:

Moles of potassium chromate =

Molar mass of potassium chromate = 194.2 g/mol

Putting values in equation 2, we get:

Hence, the number of moles of potassium chromate are and mass is 5.51 g.

Molarity of ammonium sulfate = 3.716 M

Volume of solution = 10.5 L

Putting values in equation 1, we get:

Now, using equation 2, we get:

Moles of ammonium sulfate = 39.018 mol

Molar mass of ammonium sulfate = 132.14 g/mol

Putting values in equation 2, we get:

Hence, the number of moles of ammonium sulfate are 39.018 moles and mass is 5155.84 grams.