Question

From tang label, a serving which is 14.2 g supplies 50 % of the recommended daily intake (RDI) of vitamin C, so 28.4g of tang supplies 100% RDI. From your results, calculate the number of mg of vitamin C that would constitute 100% RDI. ie how much mg of Vitamin C is in 28.4g of tang?

Remark: Mass of tang = 3.186 g

the volume of NaOH against tang= 24.29 ml

the volume of NaOH against vitamin C=26.30 ml

Molarity of NaOH = 0.0502 M

Answer 1

for 3.186 g of tang

amount of NaOH used = 26.30mL

since 1 mole of NaOH react with 1 mole of vitamin C

moles of NaOH reacted = moles of vitamin C reacted

moles of NaOH reacted = molarity * volume = 0.0502 *26.30 = 1.32 mmoles

moles of vitamin c reacted = 1.32 mmoles

amount of vitamin c present in 3.186 g of tang = 1.32 * 176.12 = 232.5 mg

amount of vitamin c present in 1 g of tang = 232.5 / 3.186 = 72.98 mg

amount of vitamin C needed for 100%RDI ( in 28.4 g of tang ) = 72.98 * 28.4 = 2072.6 mg