second part

Question 1

difference between my source and internet source

Answer 1

on comparing my results to the internet source its clear that my results are higher (values greater than sign) calculate percentage decrease

Question 2

however…

Answer 2

all my results clearly show that the berry juice has the greatest vitamin c concentration with 84mg (74 internet source)

Question 3

conclusion

Answer 3

the mass of vit c present in each of the juices is (name values) thus the juice with the greatest mass of vit c present is the berry juice these results are in accordance with the internet source, the tropicanna website which cites the berry juice having the greatest mass of vit C present (74mg)

Question 4

Evaluation 1

Answer 4

my internet source should be reliable as it came from the manufacturers website therefore it must comply with all food standard regulations and the information must be verified by a food scientist

Question 5

evaluation 2

Answer 5

starch was a good indictor to use as it gave a sharp endpoint to the reaction therefore the volume of iodine solution used could be more accurately measured, this would make the calculation of the mass of vit c more accurate

Question 6

evaluation 3

Answer 6

on comparing my results to the internet source its clear that my results are significantly higher (name values) this could have been because the juices used contained other compounds which could have reacted with the iodine solution, within the limits of my experiment there was little I could do about this to combat this a different chemical could have been used instead of iodine solution, this could have resulted In only the vitamin c being oxidised and not any other compounds, this could have made the volume of iodine used more accurate therefore the mass of vit c present could be more accurately calculated, this could have made my data closer to the source data

Question 7

evaluation 4

Answer 7

some of the volumes of iodine used were very small this could have affected how precise some of my volumes of iodine solution were to combat this a 50cm3 burette could have been used instead of a 25cm3 burette this would have made the volume of iodine solution used twice as large this could have ,ade my results more precise thus giving a better indication of the mass of vit c present in the juice