Chemistry Molarity help please!?
2017-10-18 1:20 pm
2. A 48.36 mL aliquot of aqueous KMnO4 was used to titrate 0.3170 g of Na2C2O4. What is the molarity of the potassium permanganate solution?
回答 (1)
2017-10-18 2:39 pm
Molar mass of Na₂C₂O₄ = (23.0×2 + 12.0×2 + 16.0×4) g/mol = 134.0 g/mol
The balanced net ionic equation for the reaction :
2MnO₄⁻(aq) + 16H⁺(aq) + 5C₂O₄²⁻(aq) → 2Mn²⁺(aq) + 8H₂O(l) + 10CO₂(g)
Mole ratio KMnO₄ : Na₂C₂O₄ = Mole ratio MnO₄⁻ : C₂O₄²⁻ = 2 : 5
No. of moles of Na₂C₂O₄ = (0.3170 g) / (134.0 g/mol) = 0.002366 mol
No. of moles of KMnO₄ = (0.002366 mol) × (2/5) = 0.0009464 mol
Molarity of KMnO₄ solution = (0.0009464 mol) / (48.36/1000 L) = 0.01957 M
The balanced net ionic equation for the reaction :
2MnO₄⁻(aq) + 16H⁺(aq) + 5C₂O₄²⁻(aq) → 2Mn²⁺(aq) + 8H₂O(l) + 10CO₂(g)
Mole ratio KMnO₄ : Na₂C₂O₄ = Mole ratio MnO₄⁻ : C₂O₄²⁻ = 2 : 5
No. of moles of Na₂C₂O₄ = (0.3170 g) / (134.0 g/mol) = 0.002366 mol
No. of moles of KMnO₄ = (0.002366 mol) × (2/5) = 0.0009464 mol
Molarity of KMnO₄ solution = (0.0009464 mol) / (48.36/1000 L) = 0.01957 M
收錄日期: 2021-04-24 00:50:08
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20171018052035AAAcvze