Mildy basic potassium permanganate reacted
with 1.25g of contaminated zinc granules to produce zinc hydroxide and solid manganese(iv)oxide.suppose 20.5ml of 0.050Molar of potassium permanganate completely reacted with contaminated zinc granules,how many moles of potassium permanganate were in 20.5ml.(B)what was the mass of zinc granules used in this reaction
3Zn + 2MnO4^- ==> 2MnO2 + 3Zn(OH)2 You an finish balancing.
(a) mol MnO4^- = M x L = ?
(b) Use the coefficients in the balanced equation to convert mol MnO4^- to mol Zn. That should be (but check to make sure my balanced equation is correct),
mol MnO4^- x (3 mol Zn/2 mol MnO46-) = ?mol MnO4^- x (3/2) = ? mol Zn.
Then g Zn = mol Zn x molar mass Zn.
To find the number of moles of potassium permanganate in 20.5 mL of a 0.050 Molar solution, we need to use the formula:
Molarity (M) = moles of solute / liters of solution
First, convert the volume of the solution from milliliters to liters:
20.5 mL = 20.5 / 1000 = 0.0205 L
Now, we can rearrange the formula to solve for moles of solute:
moles of solute = Molarity × liters of solution
moles of solute = 0.050 mol/L × 0.0205 L
moles of solute = 0.001025 mol
Therefore, there are 0.001025 moles of potassium permanganate in 20.5 mL of the solution.
Now, to find the mass of zinc granules used in the reaction, we can use the balanced chemical equation:
2 KMnO₄ + 5 Zn → K₂Zn(OH)₄ + 2 MnO₂
According to the equation, 2 moles of potassium permanganate react with 5 moles of zinc. Therefore, the mole ratio is 2:5.
Since we know the number of moles of potassium permanganate (0.001025 mol), we can use the mole ratio to find the moles of zinc:
moles of zinc = (0.001025 mol KMnO₄) × (5 mol Zn / 2 mol KMnO₄)
moles of zinc = 0.0025625 mol
To find the mass of zinc granules, we can use the formula:
mass = moles × molar mass
The molar mass of zinc (Zn) is approximately 65.38 g/mol.
mass = 0.0025625 mol × 65.38 g/mol
mass = 0.1672 g
Therefore, the mass of zinc granules used in this reaction is 0.1672 grams.