In this experiment, iodine is

• oxidized to I^- (I 1 minus)
• oxidized to IO₃ ^- (I O3 1 minus)
• reduced to I^- (I 1 minus)
• oxidized to IO^- (I O 1 minus)
• reduced to IO₃ ^- (I O3 1 minus)
• reduced to IO^- (I O 1 minus)

reduced to I^- (I 1 minus)

In this experiment, what reacts with the starch to turn it purple?

• excess dehydroascorbic acid.
• excess iodine.
• excess iodide ion.
• excess ascorbic acid.

excess iodine.

In the balanced redox reaction between I₂ and ascorbic acid, which of the following is true?

• 1 mole I₂ reacts with 1 mole ascorbic acid
• 2 mole I₂ reacts with 1 mole ascorbic acid
• 3 mole I₂ reacts with 1 mole ascorbic acid
• 1 mole I₂ reacts with 3 mole ascorbic acid
• 1 mole I₂ reacts with 2 mole ascorbic acid

1 mole I₂ reacts with 1 mole ascorbic acid

How many moles of ascorbic acid can be reacted with 0.00013 moles of I₂ in this experiment?

0.00013 moles

A redox titration similar to this one requires 30.65 mL of iodine solution to titrate a sample containing 25.00 mL of 0.0002487 M ascorbic acid to the end point. What is the molarity of the iodine?

• 0.0002029 M
• 0.2029 M
• 0.2487 M
• 0.0003049 M
• 0.0002487 M
• 0.3049 M

0.0002029 M

Ex.

M_asc x V_asc = M_I2 x V_I2

M_I2 = (0.0002487 x 25 ) / (30.65)

M_I2 = 0.0002029 M