[求助] biology multiple choice

A.

O.N. of Cr in L.H.S. = -2+8 = +6
O.N. of Cr in R.H.S. = (-2+14)/2 = +6
O.N. of H in both sides = +1
=> B,C,D are wrong.

[CrO4]2- is yellow while [Cr2O7]2- is orange. => A.
unlock-YM 發表於 5/3/2010 08:21 PM

                               
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謝謝你^^唔介意我問多一題>
小霞的fans 發表於 6/3/2010 07:58 PM

                               
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n x 4/3 x 3 = 4n atoms?

Mole數係唔一樣...
unlock-YM 發表於 6/3/2010 12:21 AM

                               
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係4n呀..

但係x4/3 x3 呢舊野點黎架@@?
小霞的fans 發表於 7/3/2010 12:07 AM

                               
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先當大家都係1 mole，咁XO3的atom數就係XO2的4/3。
佢話3 moles，咁再乘三就係答案。
unlock-YM 發表於 6/3/2010 04:12 AM

                               
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oxygen is present in O2 under normal condition, but sulphur is S
so the no of mole of S is 2/32 while O is 1/32...
RX78-2 發表於 7/3/2010 05:16 PM

                               
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one mole of sulphur atoms has a mass twice that of one mole of oxygen atoms.which of the following statement(s) is/are correct ?

2. 2g of sulphur and 1g of oxygen each contain the same number of atoms
點解呢句錯既!?佢地既atom數量唔係都係=(mole x avogadro constant)1x6.02x10^23 咁多架咩???
小霞的fans 發表於 7/3/2010 14:40

                               
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97年第34條...?

fish 發表於 8/3/2010 01:34 AM

                               
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