Mixture calcium bromide and sodium bromide dissolved water

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b. Calculate the mass of sulfur dioxide in a sample of air if 7.37mL of 0.00800M of potassium permanagante solution is required for the titration.

25. Acetylsalicylic acid (CH3O4) is a monoprotic acid. A small amount of this compound is found in aspirin tablet. In an experiment to determine the composition, an aspirin tablet was crushed and dissolved in water. It took 12.25 mL of 0.0733M calcium hydroxide to neutralize the solution. Calculate the number of grains of aspirin in the tablet (1 grain = 0.0648g) 26. Oxalic acid is present in many plants and vegetable. Potassium permanagate is used in an analysis which produced carbon dioxide gas and manganese (II) ions. If 24.0mL of 0.0100M Potassium permanagate is needed to titrate 1.00g sample, what is the mass percent of oxalic acid in the sample? (Note: write a balance equation before)

Problem 24: Titration of Sulfur Dioxide

a. The balanced chemical equation for the titration of sulfur dioxide (SO2) with potassium permanganate (KMnO4) in an acidified solution is:

• Volume of KMnO4 solution used = 7.37 mL = 0.00737 L

• Molarity of KMnO4 solution (KMnO4) = 0.00800 M

= 5.896 x 10^-5 mol

2. Since the reaction ratio between SO2 and KMnO4 is 5:2 (from the balanced equation), moles of SO2 are also in a 5:2 ratio with respect to moles of KMnO4.

5. Calculate the mass of SO2:

Mass of SO2 = Moles x Molar mass Mass of SO2 = 1.474 x 10^-4 mol x 32.07 g/mol ≈ 0.00473 g

C9H8O4 + 2 Ca(OH)2 ⟶ Ca(C9H7O4)2 + 2 H2O

From the balanced equation, you can see that one mole of aspirin reacts with two moles of calcium hydroxide.

3. Calculate the moles of calcium hydroxide used in the titration:

Moles of Ca(OH)2 = Volume (L) x Molarity Moles of Ca(OH)2

5. Calculate the mass of aspirin in grams:

Mass of aspirin = Moles x Molar mass of aspirin

Number of grains ≈ 0.3232 g / 0.0648 g/grain ≈ 4.983 grains

So, there are approximately 4.983 grains of aspirin in the tablet.

From the balanced equation, you can see that 5 moles of oxalic acid react with 2 moles of potassium permanganate.

2. Given:

Moles of KMnO4 = Volume (L) x Molarity

Moles of KMnO4 = 0.0240 L x 0.0100 mol/L = 2.40 x 10^-4 mol

Molar mass of C2H2O4 = (2 x 12.01 g/mol) + (2 x 1.01 g/mol) + (4 x 16.00 g/mol) = 90.02 g/mol

6. Calculate the mass of oxalic acid in grams:

Mass percent = (0.0540 g / 1.00 g) x 100 ≈ 5.40%

So, the mass percent of oxalic acid in the sample is approximately 5.40%.

1. • NaBr: Atomic mass of Na + Atomic mass of Br = 22.99 g/mol + 79.90 g/mol = 102.89 g/mol

2. Calculate the moles of AgBr (silver bromide) formed from the mass of the precipitate: Moles of AgBr = Mass of precipitate / Molar mass of AgBr

5. Calculate the mass of NaBr in the mixture:

Mass of NaBr = Moles of NaBr * Molar mass of NaBr

So, the mass percent of sodium bromide in the mixture is approximately 88.59%.

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