To titrate the acetic acid in 10.0 mL of vinegar sample, 25.5mL of 0.5M sodium hydroxide solution is needed. What is the concentration of acetic acid in the vinegar?
mols NaOH = M x L = ?
mols acetic acid = mols NaOH since the reaction is 1 mol acetic acid = 1 mol NaOH.
Then M acetic acid = mols acetic acid/L acetic acid.
Step 1: Determine the balanced chemical equation
In this case, acetic acid (CH3COOH) reacts with sodium hydroxide (NaOH) to form sodium acetate (CH3COONa) and water (H2O):
CH3COOH + NaOH → CH3COONa + H2O
Step 2: Calculate the number of moles of sodium hydroxide used
Using the equation:
Number of moles = volume (L) × concentration (mol/L)
Given:
Volume of sodium hydroxide (NaOH) = 25.5 mL = 0.0255 L
Concentration of sodium hydroxide (NaOH) = 0.5 M
Number of moles of sodium hydroxide (NaOH) = 0.0255 L × 0.5 mol/L
Step 3: Calculate the stoichiometry
From the balanced chemical equation, the mole ratio between acetic acid and sodium hydroxide is 1:1. This means that 1 mole of acetic acid reacts with 1 mole of sodium hydroxide.
Step 4: Calculate the number of moles of acetic acid
Since the moles of acetic acid and sodium hydroxide are the same, the number of moles of acetic acid is also equal to:
Number of moles of acetic acid = 0.0255 mol
Step 5: Calculate the concentration of acetic acid in the vinegar
Given: Volume of vinegar sample = 10.0 mL = 0.01 L
The concentration of acetic acid (CH3COOH) in the vinegar is given by:
Concentration of acetic acid = Number of moles of acetic acid / Volume of vinegar sample
Concentration of acetic acid = 0.0255 mol / 0.01 L
Step 6: Calculate the final concentration
Concentration of acetic acid = 2.55 M
Therefore, the concentration of acetic acid in the vinegar sample is 2.55 M.
To find the concentration of acetic acid in the vinegar sample, we need to calculate the number of moles of acetic acid and then divide by the volume of the vinegar sample.
The balanced chemical equation for the reaction between acetic acid (CH3COOH) and sodium hydroxide (NaOH) is:
CH3COOH + NaOH → CH3COONa + H2O
From the equation, we can see that the mole ratio between acetic acid and sodium hydroxide is 1:1. This means that the number of moles of acetic acid is equal to the number of moles of sodium hydroxide used in the titration.
First, let's calculate the number of moles of sodium hydroxide used:
Moles of sodium hydroxide = concentration (mol/L) × volume (L)
Moles of sodium hydroxide = 0.5 mol/L × 0.0255 L
Moles of sodium hydroxide = 0.01275 mol
Since the mole ratio between acetic acid and sodium hydroxide is 1:1, the number of moles of acetic acid in the vinegar sample is also 0.01275 mol.
Now, we need to calculate the concentration of acetic acid in the vinegar:
Concentration of acetic acid (mol/L) = moles of acetic acid / volume of vinegar (L)
Concentration of acetic acid (mol/L) = 0.01275 mol / 0.01 L
Concentration of acetic acid (mol/L) = 1.275 mol/L
Therefore, the concentration of acetic acid in the vinegar is 1.275 mol/L.