Acid Content of Vinegar

n(NaOH) = c × v

= 0.1 × 0.02945

n = 0.002945 mol

n(CH3COOH) = 0.002945 mol (n(NaOH) and n(CH3COOH) are a 1:1 ratio)

m = n

                                                                mr

mass(CH3COOH) = 0.002945 × 60

= 0.1767 grams

The mass of ethanoic acid in the sample of Aceto vinegar is: 0.15906g

n(NaOH) = c × v

= 0.1 × 0.02651

n = 0.002651 mol

n(CH3COOH) = 0.002651 mol

m = n

                                                                mr

mass(CH3COOH) = 0.002651 × 60

= 0.15906 grams

The mass of ethanoic acid in the sample of Cornwalls vinegar is: 0.15906g

n(NaOH) = c × v

= 0.1 × 0.02046

n = 0.002046 mol

n(CH3COOH) = 0.002046 mol

m = n

                                                                mr

mass(CH3COOH) = 0.002046 × 60

= 0.12276 grams

2) Calculate the average concentration of ethanoic acid in the vinegar as a percentage by mass.

The average concentration of ethanoic acid in the Morrow vinegar is 5.87 % w/w.

c = amount of solute × 100

                                                     amount of solvent

c = 0.1767 × 100

                                                               3.01

c = 5.87 % w/w

The average concentration of ethanoic acid in the Aceto vinegar is 5.28 % w/w.

c = 0.15906 × 100

                                                               3.013

c = 5.28 % w/w

The average concentration of ethanoic acid in the Cornwalls vinegar is 4.06 % w/w.

c = 0.12276 × 100

                                                               3.027

c = 4.06 % w/w

3) Calculate the cost of one gram of ethanoic acid in your brand of vinegar as a percentage by mass.

The cost of one gram of ethanoic acid in Morrow vinegar is 7.56c.

5.87 grams in 100 grams

500÷100= 5

5×5.87= 29.35 grams of ethanoic acid in 500ml of Morrow vinegar

29.35 grams cost $2.22

2.22÷29.35 = $0.0756

1 g = 7.56 cents

The cost of one gram of ethanoic acid in Aceto vinegar is 15.11c.

5.28 grams in 100 grams

500÷100= 5

5×5.28= 26.40 grams of ethanoic acid in 500ml of Aceto vinegar

26.40 grams cost $3.99

3.99÷26.40 = $0.151136

1 g = 15.11 cents

 The cost of one gram of ethanoic acid in Cornwalls vinegar is c.

4.06 grams in 100 grams

375÷100= 3.75

3.75×4.06= 15.225 grams of ethanoic acid in 375ml of Cornwalls vinegar

15.225 grams cost $1.79

1.79÷15.225 = $0.11757

1 g = 11.76 cents

4) If different members of your class used different brands of vinegar, which brand appears to be the best value for money based on ethanoic acid content?

Based on ethanoic acid content, Morrow vinegar appears to have the best value. Morrow is the cheapest, with 1 gram costing 7.56cents, Cornwalls is the second, with 1 gram costing 11.76 cents, and Aceto vinegar is the most expensive, with 1 gram costing 15.11 cents.

5) Write an equation for the reaction that occurs between the ethanoic acid and the sodium hydroxide.

Ethanoic acid and sodium hydroxide react together to form products: sodium acetate and water.

CH3COOH(aq) + NaOH (aq)                   CH3COONa(aq) + H2O(l)