A solution of potassium permanganate reacts with oxalic acid, H2C2O4, to form carbon dioxide and solid manganese(IV) oxide (MnO2). Write a balanced net ionic equation for the reaction. If 20.0 mL of 0.300 M potassium permanganate are required to react with 15.0 mL of oxalic acid, what is the molarity of the oxalic acid? What is the mass of the manganese(IV) oxide formed

Respuesta :

Answer:

The molarity of oxalic acid is 0.6 M

There is 0.522 grams of manganese oxide formed.

Explanation:

Step 1: The balanced equation

MnO4- + 3e- +4H+ → MnO2 + 2H2O

H2C2O4 → 2CO2 + 2H+ + 2e-

2H+ + 2MnO4- + 3H2C2O4 → 2MnO2 + 6CO2 + 4H2O

Step 2: Data given

20.0 mL of 0.300 M potassium permanganate ( KMnO4)

volume of oxalic acid = 15.0 mL

Step 3:  Calculate moles of KMnO4

Number of moles KMn04 = Molarity KMnO4 * Volume KMnO4

Moles of KMnO4 = 0.300 M * 0.02 L = 0.006 mol KMnO4

Step 4: Calculate moles of H2C2O4

For 2 moles KMnO4 consumed, we need 3 moles of H2C2O4

For 0.006 moles of KMnO4, we need 0.006 *3/2 = 0.009 moles of H2C2O4

Step 5: Calculate molarity of H2C2O4

Molarity = moles / volume

Molarity = 0.009 moles / 0.015 L

Molarity = 0.6 M

Step 6: Calculate moles of MnO2

For 2 moles KMnO4 consumed, we need 3 moles of H2C2O4, to produce 2 moles of MnO2

So for 0.006 moles of KMnO4 we have 0.006 moles of MnO2

Step 7: Calculate mass of MnO2

Mass MnO2 = Moles of MnO2 * Molar mass MnO2

Mass MnO2 = 0.006 moles * 86.937 g/mol = 0.522 grams

There is 0.522 grams of manganese oxide formed.