杰少仔 發表於 2006-2-8 22:24:10

AL Chem

測定NaOH 及Na2CO3的摩爾濃度: (双指示劑)

I NaOH + HCl -> NaCl + H2O   phenolphthalein
IIa Na2CO3 + HCl -> NaHCO3 + NaCl    phenolphthalein
IIb NaHCO3 + HCl -> NaCl + H2O + CO2    methyl orange

酸加入NaOH和Na2CO3混合物，用phenolphthalein｜反應I , IIa finish，之後加methyl orange，IIb finish。

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測定Na2CO3 及NaHCO3的摩爾濃度

Ia Na2CO3 + HCl -> NaHCO3 + NaCl    phenolphthalein
Ib NaHCO3 + HCl -> NaCl + H2O + CO2methyl orange
II NaHCO3 + HCl -> NaCl + H2O + CO2methyl orange

用phenolphthalein，反應Ia finish，再加methyl orange，Ib, II finish。

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知道:
HCl = 0.0531M
HCl = x cm^3 (落左幾多)

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如果已經求灑NaOH,Na2CO3,Na2CO3,NaHCO3既濃度
咁點求混合物百分比?
兩part計既野一唔一樣?

2076 發表於 2006-2-8 22:47:52

邊個topic黎架?:icon101:

MatthewChor 發表於 2006-2-9 23:37:04

Mixture is only NaOH + Na2CO3?
but is it hv 2 Na2CO3?:icon101:

actually 2 parts are doing the same thing...:)
just the target changes

[ 本帖最後由 MatthewChor 於 2006-2-911:41 PM 編輯 ]

杰少仔 發表於 2006-2-10 00:08:40

原來好低能
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