chemistry-chemical cell

Larry

2011-06-19 1:49 am

圖片參考：http://img837.imageshack.us/img837/777/32782429.jpg

a) Which electrode is cathode? Write the corresponding half ionic equation

b) What is the direction of the electron flow?

c)Write the observations at both half cells.

回答 (1)

[匿名]

2011-06-19 3:18 am

✔ 最佳答案

a) Cathod is the electrode where redction occurs. Since reduction occurs at carbon electrode Y, it is the cathode.
half equation: Fe3+ + e- ---> Fe2+

b) Electron flows from electrode X to electrode Y through external circuit.

c) The yellow color of iron(III) sulphate solution becomes paler, as it is reduced to pale green Fe2+ ions and hence the conc. of iron (III) ions in the soltuon decreases.

The KI solution turns dark blue because iodide ion is oxidized to iodine which forms a dark blue complex with starch.

參考: me

👍 0 👎 0