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A-Level Group 7 Chemistry help

Hi I’m stuck on this question on Group 7 Chemistry:


In acidic solution, IO3- ions oxidise iodide ions to iodine.

IO3- + 5I- + 6H+ 3I2 + 3H2O

Give a half-equation for the oxidation of iodide ions to iodine.
Deduce the half-equation to show the reduction process in this reaction.
Original post by MiniYamini0328
Hi I’m stuck on this question on Group 7 Chemistry:
In acidic solution, IO3- ions oxidise iodide ions to iodine.
IO3- + 5I- + 6H+ 3I2 + 3H2O
Give a half-equation for the oxidation of iodide ions to iodine.
Deduce the half-equation to show the reduction process in this reaction.

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Reply 2
Original post by MiniYamini0328
Hi I’m stuck on this question on Group 7 Chemistry:
In acidic solution, IO3- ions oxidise iodide ions to iodine.
IO3- + 5I- + 6H+ 3I2 + 3H2O
Give a half-equation for the oxidation of iodide ions to iodine.
Deduce the half-equation to show the reduction process in this reaction.

2I- --> I2 + 2e-

The two half equations involved here combine to make the ionic equation given in the question. So, can you work out the second half equation?
Reply 3
Original post by Methene
2I- --> I2 + 2e-
The two half equations involved here combine to make the ionic equation given in the question. So, can you work out the second half equation?


Thank you!! Would the second one be 2IO3- + 12H+ + 10e- —> I2 + 6H2O ?
Original post by MiniYamini0328
Thank you!! Would the second one be 2IO3- + 12H+ + 10e- —> I2 + 6H2O ?

Yes
Reply 5
Original post by MiniYamini0328
Thank you!! Would the second one be 2IO3- + 12H+ + 10e- —> I2 + 6H2O ?

Yep! Good job :smile:
Reply 6
Original post by MiniYamini0328
Hi I’m stuck on this question on Group 7 Chemistry:
In acidic solution, IO3- ions oxidise iodide ions to iodine.
IO3- + 5I- + 6H+ 3I2 + 3H2O
Give a half-equation for the oxidation of iodide ions to iodine.
Deduce the half-equation to show the reduction process in this reaction.

Oxidation half-equation: This involves the loss of electrons. For the iodide ions (I⁻) being oxidized to iodine (I₂), the half-equation is:
2I→I2​+2e−
Reduction half-equation: This involves the gain of electrons. For the iodate ions (IO₃⁻) being reduced, the half-equation is:
IO3 + 6H+ + 5e−→3/2 ​I2 ​+ 3H2​O

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