Potassium permanganate, KMnO4, a common oxidizing agent, is made from various ores that contain manganese (IV) oxide, MnO2. The equation shows the net reaction for one process that forms potassium permanganate
2MnO2+2KOH+O2=2KMnO4+H2
What is the maximum mass, in kilograms, of KMnO4 that can be made from the reaction of 934.98 g of MnO2 with 432.53 g of KOH and excess oxygen gas?
This is just another stoichiometry problem. Find your post above and follow the same guidelines.
To find the maximum mass of KMnO4 that can be made from the given reaction, we need to determine the limiting reactant. The limiting reactant is the reactant that will be completely consumed first and determines the maximum amount of product that can be formed.
Let's calculate the number of moles of each reactant:
1. Moles of MnO2:
Given mass of MnO2 = 934.98 g
Molar mass of MnO2 = 55.85 g/mol + 16.00 g/mol = 71.85 g/mol
Moles of MnO2 = given mass / molar mass = 934.98 g / 71.85 g/mol ≈ 12.99 mol
2. Moles of KOH:
Given mass of KOH = 432.53 g
Molar mass of KOH = 39.10 g/mol + 16.00 g/mol + 1.01 g/mol = 56.11 g/mol
Moles of KOH = given mass / molar mass = 432.53 g / 56.11 g/mol ≈ 7.70 mol
Now, we need to compare the stoichiometric ratios of MnO2 and KOH in the balanced equation to determine which reactant is limiting.
From the balanced equation:
2MnO2 + 2KOH + O2 → 2KMnO4 + H2
The stoichiometric ratio between MnO2 and KMnO4 is 2:2, i.e., 1:1.
The stoichiometric ratio between KOH and KMnO4 is 2:2, i.e., 1:1.
Comparing the moles of MnO2 and KOH:
Moles of MnO2 = 12.99 mol
Moles of KOH = 7.70 mol
Since the stoichiometric ratio for both reactants is 1:1 with KMnO4, the limiting reactant is the one with a smaller number of moles. In this case, the limiting reactant is KOH.
Now, let's calculate the maximum mass of KMnO4 that can be formed from the limiting reactant.
Moles of KMnO4 formed = Moles of KOH = 7.70 mol
Molar mass of KMnO4 = (39.10 g/mol + 54.94 g/mol + 16.00 g/mol) + (4.03 g/mol) = 158.03 g/mol
Maximum mass of KMnO4 = Moles of KMnO4 formed × molar mass of KMnO4
= 7.70 mol × 158.03 g/mol ≈ 1216.81 g
Finally, convert the mass to kilograms:
Maximum mass of KMnO4 = 1216.81 g = 1.21681 kg
Therefore, the maximum mass of KMnO4 that can be made from the given reaction is approximately 1.21681 kilograms.