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The amount of ascorbic acid (vitamin C; C₆H₈O₆ )in tablets is determined by reaction with bromine and then titration of the hydrobromic acid with standard base:
C₆H₈O₆(aq) + Br₂(aq) → C₆H₆O₆(aq) + 2HBr(aq)
HBr(aq) + NaOH(aq) → NaBr(aq) + H₂O(l)
A certain tablet is advertised as containing 500 mg of vitamin C. One tablet was dissolved in water and reacted with Br₂. The solution was then titrated with 43.20 mL of 0.1350 M NaOH. Did the tablet contain the advertised quantity of vitamin C?

Respuesta :

Yes, the tablet contains the advertised quantity of Vitamin C.

What is titration Analysis for Acid and Base?

  • The process of determining the amount of an acid or base through a neutralization reaction is referred to as titration analysis.
  • The titration's endpoint indicates that the moles of acid and base that have reacted is equal to their stoichiometric ratio in the balanced chemical equation.

To find that tablets contain the advertised quantity of vitamin C:

The equation for the reaction of ascorbic acid and bromine is:

  • C₆H₈O₆ + Br₂ → 2HBr + C₆H₈O₆

The following equation describes the reaction between HBr and NaOH:

  • HBr + NaOH → NaBr + H₂O

We can calculate the moles of NaOH that reacted and determine the moles of HBr from the second reaction.

  • moles NaOH = (0.135 M)(0.043 L) = 5.805 × 10⁻³ mol
  • moles HBr = moles NaOH = 5.805 × 10⁻³ mol

Then, we can calculate the moles of ascorbic acid in the sample from the second reaction.

  • moles C₆H₈O₆ = 5.805 × 10⁻³ mol HBr × (1 mol C₆H₈O)/(2 mol HBr) = 2.29025 10⁻³ mol

Converting this to mass (Molar mass = 176.12 g/mol):

  • mass C₆H₈O₆ = (2.29025 10⁻³ mol)(176.12 g/mol)(1000 mg/1 g)
  • mass C₆H₈O₆ = 511 mg

Therefore, yes, the tablet contains the advertised quantity of Vitamin C.

Know more about titration analysis for acid and base here:

https://brainly.com/question/22772236

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