Question

How many milliliters of 0.84M magnesium sulfate solution must be added to an existing volume of 173 mL of pure water in a flask to achieve a solution that is 0.20M with regards to sulfate ion concentration? Type answer:

Answer 1

To achieve a solution that is 0.20M with regards to sulfate ion concentration, 95 mL of the 0.84M magnesium sulfate solution must be added to 173 mL of pure water.

Step-by-step explanation:

To calculate the volume of the magnesium sulfate solution needed, we can use the equation:

M1V1 = M2V2

Where M1 is the initial molarity, V1 is the initial volume, M2 is the final molarity, and V2 is the final volume.

In this case, the initial molarity is 0.84M, the initial volume is 0.173 L (since 173 mL is equivalent to 0.173 L), the final molarity is 0.20M, and the final volume is the sum of the initial volume (0.173 L) and the volume of the magnesium sulfate solution we want to find.

Plugging in the values:

(0.84M)(0.173 L) = (0.20M)(0.173 L + V2)

After solving for V2, we find that the volume needed is 0.095 L (or 95 mL) of the 0.84M magnesium sulfate solution.

Answer 2

To achieve a 0.20M sulfate ion concentration, approximately 41.67 mL of a 0.84M magnesium sulfate solution must be added to 173 mL of water in a flask.

Step-by-step explanation:

To calculate the volume of 0.84M magnesium sulfate solution needed, we can use the formula for dilution:

C1V1 = C2V2

Where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.

In this case, our initial volume is 173 mL and our final volume (after adding the magnesium sulfate solution) is V2 + 173 mL. The final concentration is 0.20M and the initial concentration is 0.84M for the magnesium sulfate solution.

Substituting the values into the formula, we get:

(0.84M)(V2) = (0.20M)(173mL)

V2 = (0.20M)(173mL) / 0.84M

V2 = 41.67 mL

Therefore, approximately 41.67 milliliters of the 0.84M magnesium sulfate solution must be added to the existing volume of 173 mL of water to achieve a solution that is 0.20M with regard to sulfate ion concentration.