Neco 2019 Biology Question 3

A student carried out a titration to determine the vitamin C (ascorbic acid) content of freshly squeezed orange juice using 2,6‑dichlorophenolindophenol (DCPIP) solution (0.001 M). The procedure was as follows: 1. 50 mL of orange juice was placed in a conical flask. 2. A few drops of starch indicator were added. 3. The juice was titrated against the DCPIP solution until the blue‑black colour disappeared. 4. A blank titration was performed with 50 mL of distilled water under identical conditions. The volumes of DCPIP used are recorded in the table below. | Trial | Volume of DCPIP (mL) | |-------|----------------------| | 1 | 12.3 | | 2 | 12.6 | | 3 | 12.1 | The blank titration gave an average volume of 0.2 mL. The molar mass of vitamin C is 176.12 g mol⁻¹. Answer the following: