Ethanol

點解ETHANOL MIX WITH WATER 會唔可以CONDUCT ELECTRIVITY ?

In the mixture of ethanol and water, both ethanol and water exist mainly as molecules. At room temperature (25oC), water molecules are only extremely slightly ionized to give 0.0000001 M hydrogen ions and 0.0000001 M of hydroxide ions, and ethanol molecules are not ionized at all. The mixture cannot conduct electricity because the concentration of mobile ions is extremely low.

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仲有就係 :１ＳＴGraphite is a rather soft substance .
２ＮＤAll the bonds between the carbon atoms in graphite are weak
邊個STATEMENT 對 OR 不對 . 點解 ?

The first statement is true. In fact, graphite is soft such that it can be used to make pencil lead. This is because the layers of carbon atoms in graphite can easily slide between each other, as they are held together by weak van der Waals’ force.

The second statement is false. The attractive forces between layers of carbon atoms are weak. However, each layer of carbon atoms is formed because all carbon atoms in the same layer are held together by strong covalent bond, and each carbon atom is strongly bonded with 3 adjacent carbon atoms with strong covalent bonds.
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ethanol:導唔導電.其實係睇水中的ion 有幾多?因為ethanol 不會contribute any ion to the water.so doesn't conducting

1st correct. they are weakly bonded by wander waals force within graphite.
2nd incorrect. the layer of graphite is bonded with wander waal's force while the bonding within layer of graphiter is covalent bond which is very strong.

ethanol 本身係唔過電
水的ion就係 1*10^-14 咁多
所以唔過電

1st statement is true
2nd statement is false

all the bonds between the carbon atoms are strong covalent bond
but the bond between graphite and graphite is weak Van Der Waals' forces

Because the electrical conductivity(導電性) of a substance is depends on the concentraction of ions (cations & anions) of a substance.

The fact is that mixing ethanol with water cannot increase the conductivity of the solution, it is because ethanol is a covalent compound (共價化合物), when dissolving ethanol into water, it cannot produce ions as it is not a ionic compound.

Since the solution have no ions, so the result is follow.

用中文簡單講，即係乙醇唔係離子化合物，所以它溶係水唔會在水中電離，產生離子。既然冇離子，就唔會有導電性。


第1個說法是正確
To begin with, you should know that graphite is a layer(層狀) structure
用中文講埋啦，石墨係片層狀的共價化合物，每一屠由每６個碳原子組成的六角環砌合而成
而整個石墨固體是每一層堆疊而成
就好似時興隆方塊酥咁

解釋係:
The attraction between the carbon atoms in the same layer is strong covalent bond（共價鍵）, while the attraction between the layers is weak intermolecular force（分子間吸引力）.
Hence, graphite is soft soluid due to the sliding property (滑動性質) of the layer structure.