今日考完chem, 有幾題mc不肯定

simon199392

1.
1st statemant
Zn reacts with water faster than Cu.
2nd statemant
Zn is more reative than Cu.

這條我選了C, 原本選A的,
因為Zn reacts with water faster than Cu E句入面,
係唔係代表左Cu都會 react with water, 但係Cu同水應該係冇反應架?
同埋Zn reacts with water, Zn唔該要steam先起到反應咩?
見到water e個字, 我應該判斷為cold water定係 all states of water呢?

2.
1st statemant
MgCl conducts electricity at room temperature.
2nd statemant
MgCl is an electrolyete.

這條我選了D, 原本選C的,
因為我唔清楚electrolyete的定義,
係指可以融響水

elven2001

1.受熱的鋅只會與水蒸氣反應,而且會爆炸...或常溫下與水,二氧化碳,氧氣等生成鹼式碳酸鋅,銅連稀硫酸都不反應...那點水有何用?
2.我不是說過溶解度與電離度無關嗎?
3.F是電子奪取體,F的泡林電負性是最高的4,O是+2價

simon199392

那麼你的選擇是?
CE的 statement記得怎樣選嗎?

問題是那點水是指cold water定係 all states of water...
CE像是也有這個water, 很含糊的說...都不知指什麼...

elven2001

3# simon199392
不要用英文簡寫....全中文好不好...本人不習慣你們的英文術語,除了有機外都不要用英文

Ivanhy92

1.
1st statemant
Zn reacts with water faster than Cu.
2nd statemant
Zn is more reative than Cu.

這條我選了C, 原本選A的,
因為Zn reacts with water faster than Cu E句入面,
係唔係代表左Cu都會 r ...
simon199392 發表於 22-6-2009 15:48

                               
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1. C
1st statement X
Water泛指 at 1 atm., 0C~100C (Liquid state)
如果唔係液體就會講明Steam/Ice

2nd statement V

2. C
1st statement x
2nd statement v
Electrolyte is a compound(ionic/molecular) which conductselectricity in molten state or in aqueous solution, anddecomposed by electricity.

3. D
Fluorine 係More electronegative than oxygen
F2O其實應該寫做OF2...
O的Oxidation number= - [2(-1)] = +2

simon199392

4# elven2001


CE是香港的會考啊, 只是問問題中的水是指什麼狀態

Ivanhy92

4# elven2001  


CE是香港的會考啊, 只是問問題中的水是指什麼狀態
simon199392 發表於 22-6-2009 16:22

                               
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絕對是Liquid state...

Gas state - 指明是Steam
Solid state - " " "Ice