Canada High School Chemisty 12 Question 求救！唔知佢想問咩

Question

Tarnish( silver sulfide) may be removed from a silver plate by placing the spoon in contact with a metallic container holding a solution of baking soda.

a) If you wanted to test this method of removing tarnish, what readily-available type of metal container would you choose.

b) Explain your answer, including half-reaction equation in your explanation.

Answer 1

a) 如果你想要嘗試用這方式移動/移走『Tarnish』，有咩類型o既容器你可以選擇。
b)答案解釋要包括反應方程式說明及解釋

2007-01-21 06:39:34 補充：
硫化氫 = sulfide 硫化氫，化合物，化學式為H2S。正常情況下是一種無色、易燃的酸性氣體，濃度低時帶惡臭，氣味如臭蛋；濃度高時反而沒有氣味(因為高濃度的硫化氫可以麻痹嗅覺神經)。它是一種急性劇毒，吸入少量高濃度硫化氫可於短時間內致命。低濃度的硫化氫對眼、呼吸系統及中樞神經都有影響。硫化氫自然存在於原油、天然氣、火山氣體和溫泉之中。它也可以在細菌分解有機物的過程中產生。硫化氫是酸性的，它與鹼及一些金屬（如銀）有化學反應。硫化氫可以用於工業上製造高純度硫磺(與二氧化硫反應);含有硫化氫的溫泉對皮膚病有一定療效.

Answer 2

a. Aluminium, because it has a lower ionization energy level.
b. When aluminium is in contact with a baking soda solution, it ionizes at the expense of silver sulphide, which is reduced to silver metal, releasing hydrogen sulphide.
3 Ag2S(s) + 2 Al(s)+ 3 H2O(l) à 6 Ag(s) + Al2O3(s) + 3 H2S(aq)
The complete explanation can be found, for example, at:
http://educ.queensu.ca/~science/main/concept/chem/c03/C03DEEA1.htm
(it is the first entry by Googling "silver tarnish removal")