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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: leas on November 22, 2018, 05:32:42 AM

Title: Titrating juice with iodine. Please help.
Post by: leas on November 22, 2018, 05:32:42 AM

Im titrating orange juice with 5% Lugols solution (6.5mg iodine per drop) to find the vitamin C concentration. I added ten drops 0.5% starch solution and need the endpoint to be at about 10 millilitres of titrant. How do I find out how many Moles I need to dilute the iodine to or how much I currently have? I thought about diluting it 250:1 to create 0.01M iodine but the endpoint won't appear so I think I'm wrong.

Thanks if anyone helps, I haven't studied chemistry before.

Title: Re: Titrating juice with iodine. Please help.
Post by: Borek on November 22, 2018, 09:51:17 AM

Quote from: leas on November 22, 2018, 05:32:42 AM

Im titrating orange juice with 5% Lugols solution (6.5mg iodine per drop)

Huge drop I would say, I would expect about five times less iodine (assuming about 20 drops per mL).

Quote

need the endpoint to be at about 10 millilitres of titrant. How do I find out how many Moles I need to dilute the iodine to or how much I currently have?

Not knowing even the approximate vit C amount you can't do much.

See if http://www.titrations.info/titrant-and-sample-volume helps