一條簡單的化學問題
2009-03-01 1:17 am
1. The following diagram shows a zinc-carbon cell.
※在此，本人已確認大家已認識zinc-carbon cell的內部結構！※
(a) Write an ionic half-equation for the reaction at the positive electrode.(1 mark)
(b) Explain the function of manganese(IV) oxide.(1 mark)
(c) The voltage of the cell drops if current is drawn from the cell rapidly. Explain briefly.(1 mark)
※以上題目是關於Dry cells in daily life和Simple chemical cells的課題！※
回答 (1)
2009-03-01 1:55 am
✔ 最佳答案
(a)2NH4+(aq) + 2MnO2(s) + 2e- → 2NH3(aq) + Mn2O3(s) + H2O(l)
(b)
Manganese(IV) oxide is used as oxidizing agent.
(to oxidize H2 to H2O)
(c)
A lot of reactants are consumed, and a lot of products are produced and accumulated at the electrodes. This increases the internal resistance of the cell and thus decreases the voltage.
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收錄日期: 2021-04-29 18:17:49
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