Question

In the table below is represented the data for a similar titration for Vitamin C analysis. Use the data below to calculate the concentration of Vitamin C in mg/mL of juice. Given that the lodine Solution used for the titration has been standardized against a known Vitamin C solution and its was determined that 1 mL of lodine - 1.50 mg Vitamin C. Buret Reading Trial 1 Trial 2 Initial Buret Reading 0.0 mL 4.8 mL Final Buret Reading 4.8 ml 9.7 ml Volume of Juice titrated 10.0 mL 10.0 mL (a) Based on the data shown in the above table, calculate the average concentration of Vitamin C in mg/mL of juice and also in g/L of juice. (b) If the RDA of Vitamin C is 75.0 mg, how many mL of the above juice must one drink?

Answer 1

Given that 1 ml of iodine solution is required to titrate 1.5mg vitamin C.

from Trail1

volume of iodine used for titrating 10ml of vitamin C containing juice =final buret reading - initial buret reading = 4.8ml -0ml= 4.8ml

from trail 2

volume of iodine used for titrating 10ml of vitamin C containing juice =final buret reading - initial buret reading = 9.7-4.8ml =4.9ml

so the average volume of iodine required to titrate 10ml of vitamin c containing juice= (4.8+4.9)/2 = 4.85 ml

we already know

1 ml of iodine solution is required to titrate 1.5mg vitamin C.

So 4.85 ml iodine is required to titrate (1.5*4.85=7.275mg) vitamin C

HENCE 7.275 mg of vitamin C is present in the 10ml vitamin C juice

concentration of vitamin C IN mg/ml = AMOUNT OF VITAMIN C/ VOLUME OF JUICE

                                                     = 7.275/10 = 0.7275 mg/ml

concentration of vitamin C In g/ l =( 0.7275 *10^-3 )/10^-3 g/l = 0.7275g/l

b) we know that 7.275 mg of vitamin C is present in the 10ml vitamin C juice

if the RDA of vitamin C is 75mg

1mg vitamin C in 10/7.275 ml juice

so 75mg in( 75*10/7.275)ml = 103.09ml