Vinegar contain ethanoic acid.titration of 3.00g of vinegar with 0.12mol NaOH solution requires 23.0cm to reach the equivalence point.what is the weight percentage of the ethanoic acid in vinegar
To find the weight percentage of ethanoic acid in vinegar, we need to determine the number of moles of ethanoic acid used in the titration.
Step 1: Calculate the number of moles of NaOH used in the titration.
Given:
- Mass of vinegar = 3.00 g
- Molar concentration of NaOH solution = 0.12 mol/L
- Volume of NaOH solution used = 23.0 cm³ or 23.0 mL
First, we need to convert the volume to liters:
Volume of NaOH solution used = 23.0 cm³ = 23.0 mL = 23.0/1000 L = 0.0230 L
Now we can calculate the number of moles of NaOH:
Moles of NaOH = Molar concentration × Volume in liters
Moles of NaOH = 0.12 mol/L × 0.0230 L
Step 2: Determine the stoichiometry between ethanoic acid and NaOH.
The balanced chemical equation for the reaction of NaOH and ethanoic acid (acetic acid) is:
CH₃COOH + NaOH → CH₃COONa + H₂O
We can see from the equation that one mole of ethanoic acid reacts with one mole of NaOH.
Step 3: Calculate the number of moles of ethanoic acid in vinegar.
Since the stoichiometry is 1:1, the number of moles of ethanoic acid is equal to the number of moles of NaOH.
Number of moles of ethanoic acid = Moles of NaOH = 0.12 mol/L × 0.0230 L
Step 4: Calculate the weight percentage of ethanoic acid in vinegar.
Weight percentage = (Mass of ethanoic acid / Mass of vinegar) × 100
Mass of ethanoic acid = Number of moles of ethanoic acid × molar mass of ethanoic acid
The molar mass of ethanoic acid (CH₃COOH) is:
Carbon (C) = 12.01 g/mol × 2 = 24.02 g/mol
Hydrogen (H) = 1.01 g/mol × 4 = 4.04 g/mol
Oxygen (O) = 16.00 g/mol + 16.00 g/mol + 1.01 g/mol = 33.01 g/mol
Molar mass of ethanoic acid = 24.02 g/mol + 4.04 g/mol + 33.01 g/mol = 61.07 g/mol
Now we can calculate the mass of ethanoic acid:
Mass of ethanoic acid = Number of moles of ethanoic acid × Molar mass of ethanoic acid
Finally, we can calculate the weight percentage:
Weight percentage = (Mass of ethanoic acid / Mass of vinegar) × 100
By following these steps and plugging in the values, you can find the weight percentage of ethanoic acid in vinegar.