關於chemical cell問題

bscat2005

2008-06-03 6:02 am

事實上係關於OA問題

1個chem.cell

負Zn 正Cu

電解質 :KNO3

16M KNO3 <<< MUST BE NO2
10M KNO3 <<<<NO???NO2????
1M KNO3 <<<<NO???H+????
0.1M KNO3 <<<<NO??H+????
0.00001M KNO3 <<<<出硬H+
NO3- 有個properties 係 dl.=NO conc. = NO2 very dl. = H+

以上4種咩情況下係 DL. VERY DL. CONC.?????出d咩

既多M先算出H+??NO??NO2???

以上所說都係OA react to weak.RA

回答 (1)

Uncle Michael

2008-06-03 10:49 am

✔ 最佳答案

(1)
At room temperature, saturated KNO3 solution is approximately 4 M. There is no 16 M KNO3 at room temperature.

(2)
Both Zn and Cu do not react with KNO3.
(Both of them can react with concentrated HNO3 to give NO2, and with dilute to moderately concentrated HNO3 to give NO. Zn reacts with very dilute HNO3 to give H2, but Cu does not.)

(3) Cell reaction
At the zinc electrode, zinc is oxidized to zinc ions.
Zn(s) → Zn2+(aq) + 2e-
Electrons moves to the copper electrode. At the copper electrode, hydrogen ions in the solution accept electrons and are thus oxidized to hydrogen gas.
2H+(aq) + 2e- → H2(g)

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