In chemistry lab the following chemicals are placed in table shelf.
1, Methyl orange, 2, 0.1 M acetic acid, 3, 0.1 KMnO4, 4, Distilled water, 5, Pure NaCl.
6, A Solution A,containing 8 grams of mixture of oxalic acid and sodium oxalate dissolved in 800mL of solution. Determine the %age impurity of solution A.
To determine the percentage impurity of Solution A, we need to calculate the amount of pure oxalic acid in the solution and compare it to the total weight of the mixture.
1. Determine the molar mass of oxalic acid (H2C2O4) and sodium oxalate (Na2C2O4).
- Molar mass of oxalic acid: 2(1.01 g/mol for hydrogen) + 2(12.01 g/mol for carbon) + 4(16.00 g/mol for oxygen) = 90.03 g/mol
- Molar mass of sodium oxalate: 2(22.99 g/mol for sodium) + 2(12.01 g/mol for carbon) + 4(16.00 g/mol for oxygen) = 133.99 g/mol
2. Calculate the weight of pure oxalic acid in Solution A using its molar mass.
- Given: 8 grams of the mixture of oxalic acid and sodium oxalate
- Let's assume x grams is the weight of pure oxalic acid in the mixture.
- The weight of sodium oxalate would be (8 - x) grams.
- To calculate the weight of pure oxalic acid, we can use the following equation:
x/(90.03 g/mol) = (8 - x)/(133.99 g/mol)
- Solve the equation for x to find the weight of pure oxalic acid.
x = (90.03 g/mol) * (8 - x)/(133.99 g/mol)
x = (90.03 g/mol) * (8 g)/(133.99 g/mol + 90.03 g/mol)
x = 5.39 grams
3. Calculate the percentage impurity of Solution A.
- The weight of impurities is the difference between the initial weight (8 g) and the weight of pure oxalic acid (5.39 g).
- Impurity weight = 8 g - 5.39 g = 2.61 g
- Percentage impurity = (Impurity weight / Total weight) * 100%
= (2.61 g / 8 g) * 100%
= 32.6%
Therefore, the percentage impurity of Solution A is 32.6%.