Electricity 3 Flashcards

1
Q

什么是分界电压?

A

能引起电解所需要的最小外加电压

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2
Q

什么是析出电位?

A

物质在阴极上发生电极反应而被还原时的最正阴极电位φc(或在阳极被氧化析出时所需的最负的阳极电位φa)

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3
Q

电解分析法分为哪两种方法?

A

控制电流电解分析法(适用只含一种金属离子;H以前金属不会析出)和控制电位电解分析法(析出电位更正的先析出)

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4
Q

完全析出时浓度?

A

10-6mol/L

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5
Q

库伦分析法的先决条件?

A

工作电极上除待测物质外没有其他任何电极反应发生,电流效率为100%

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6
Q

什么是电流效率100%?

A

电解时电极上只发生主反应,不发生副反应

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7
Q

影响电流效率的因素

A

电极自身的反应(可采用惰性电极)、溶剂的电极反应(主要是H+和OH-,通过控制工作电极电位可解决)、电解质中杂质的电解反应(通过提纯或者做空白校正方法消除)、溶液中可溶性气体的电极反应(主要指微量氧,可通N2除去)、电解产物的副反应。

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8
Q

库伦分析法的计算公式?

A

法拉第电解定律m=MQ/nF
dQ=idt
F=96485C·mol-1

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