Question

Can anyone help me, how to calculate titratable acidity of Apple juice on malic acid basis when 0.1 N KOH is used and the volume consumed of KOH is 1.1ml and 10 ml of juice is used with dilution factor 5? Help, please.

Answer 1

To calculate the titratable acidity of apple juice on a malic acid basis using the given information, you need to consider the volume and concentration of the KOH solution used, as well as the dilution factor. Here's how you can perform the calculation:

1. Determine the normality of the KOH solution: The given information states that 0.1 N (normality) KOH is used. Normality is a concentration unit that represents the number of equivalents of the solute per liter of solution. In this case, the normality is 0.1 N, meaning that there are 0.1 equivalents of KOH in 1 liter of solution.

2. Calculate the number of equivalents of KOH used: The volume consumed of KOH is given as 1.1 ml. Since the normality of KOH is 0.1 N, you can calculate the number of equivalents of KOH used as follows:

   Equivalents of KOH = Normality × Volume (in liters) Equivalents of KOH = 0.1 N × (1.1 ml / 1000 ml/L) Equivalents of KOH = 0.00011 equivalents of KOH

3. Determine the dilution factor: The given information states that 10 ml of juice is used with a dilution factor of 5. The dilution factor represents the ratio of the final volume to the initial volume. In this case, the final volume is 10 ml, and the initial volume is 10 ml × 5 = 50 ml (due to the dilution factor of 5).

4. Calculate the volume of undiluted juice: To determine the volume of undiluted juice, divide the final volume by the dilution factor:

   Volume of undiluted juice = Final volume / Dilution factor Volume of undiluted juice = 10 ml / 5 Volume of undiluted juice = 2 ml

5. Calculate the acidity of the juice: The acidity is measured in terms of the equivalents of malic acid. Since malic acid has two acidic hydrogens, one equivalent of malic acid is equal to half an equivalent of KOH. Therefore, you can calculate the acidity of the juice as follows:

   Acidity of the juice (in equivalents) = (Equivalents of KOH / 2) × (Volume of undiluted juice / 1000 ml/L) Acidity of the juice (in equivalents) = (0.00011 equivalents of KOH / 2) × (2 ml / 1000 ml/L) Acidity of the juice (in equivalents) = 0.00011 equivalents of malic acid

Thus, the titratable acidity of the apple juice on a malic acid basis, when 0.1 N KOH is used, with a volume consumed of 1.1 ml and 10 ml of juice used with a dilution factor of 5, is 0.00011 equivalents of malic acid.