Question

to measure the concentration of an aqueous solution of , an analytical chemist adds strong acid to a sample of the solution and titrates it to the endpoint with of potassium permanganate solution.the balanced chemical equation for the reaction is:what kind of reaction is this?precipitationacid-baseredoxif you said this was a precipitation reaction, enter the chemical formula of the precipitate.if you said this was an acid-base reaction, enter the chemical formula of the reactant that is acting as the base.if you said this was a redox reaction, enter the chemical symbol of the element that is oxidized.calculate the mass percent of in the sample. be sure your answer has the correct number of significant digits.

Answer 1

The mass percent of citric acid in the candy sample is 5.83%.

The chemical equation for the reaction is:

C₂H₂O(CO₂H)₃ (aq) + 3OH⁻ (aq) → C₂H₂O(CO₂)₃ (aq) + 3H₂O (l)

This is a neutralization reaction, which is a type of acid-base reaction. The citric acid is the acid in the reaction, and the sodium hydroxide is the base. The products of the reaction are a salt (citrate salt) and water.

To calculate the mass percent of citric acid in the sample, we can use the following equation:

mass percent citric acid = (mass of citric acid / mass of sample) * 100%

We know that the mass of the sample is 16.00 g. The mass of citric acid can be calculated using the following equation:

We know that the volume of NaOH solution is 14.2 mL and the molarity of NaOH solution is 0.340 M. Substituting these values into the equation, we get:

moles of citric acid = 14.2 mL * 0.340 M = 4.87 mmol

The molar mass of citric acid is 192.12 g/mol. Substituting this value into the equation for mass of citric acid, we get:

mass of citric acid = 4.87 mmol * 192.12 g/mol = 0.932 g

Now we can calculate the mass percent of citric acid in the sample:

mass percent citric acid = (0.932 g / 16.00 g) * 100% = 5.83%