Quantitative Analysis of a Mixture of Carbonates
(Inquiry-Based Approach)
定量分析 — 碳酸鹽的混合物 (探究為本實驗)
There are some possible methods for the
analysis.
1. Measure the mass of insoluble calcium carbonate
residue after filtration
2A. Precipitation between barium chloride and
filtrate
2B. Titration between filtrate and standard strong
acid
3. Direct titration
4. Back titration
此定量分析可行的一些方法：
方法一 （利用過濾法測定不溶於水的碳酸鈣）
方法二甲（利用氯化鋇與濾液反應生成的沉澱物作測定）
方法二乙（用標準強酸與濾液進行滴定）
方法三（直接滴定法）
方法四（返滴定法）
Method
1
- Measure the
mass of insoluble calcium carbonate residue after filtration
方法一 （利用過濾法測定不溶於水的碳酸鈣）
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Weigh a sample of the unknown mixture accurately. 稱量樣本以得出樣本的重量。 |
|---|---|
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Stir the sample with water. 將樣本溶於水中並加以攪拌。 |
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Filter the suspension. 過濾。 |
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Take out the filter paper. 取出濾紙。 |
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Put the filter paper into an oven. Dry and weigh the mass of the residue collected. 將濾紙放進焗爐。 乾燥並稱量殘留物的重量。 |
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Method
2A -
Precipitation between barium chloride and filtrate
方法二甲（利用氯化鋇與濾液反應生成的沉澱物作測定）
 |
1.0 M Barium chloride solution 1.0 M 氯化鋇溶液 |
|---|---|
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Weigh a sample of unknown mixture accurately. 稱量樣本以得出樣本的重量。 |
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Stir the sample with water. 將樣本溶於水中並加以攪拌。 |
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Filter the suspension to collect the filtrate. 透過過濾法得到濾液。 |
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Add an excess amount of barium chloride solution to the filtrate to precipitate out the carbonates ions. 加入過量的氯化鋇到濾液中，這種方法會生 成不溶於水的碳酸鋇。 |
|
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Filter the suspension. 過濾。 |
 |
Take out the filter paper. 取出濾紙。 |
 |
Put the filter paper into an oven. Dry and weigh the mass of the residue collected. 將濾紙放進焗爐。 乾燥並稱量殘留物的重量。 |
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Method 2B
- Titration between filtrate and standard strong
acid
方法二乙（用標準強酸與濾液進行滴定）
 |
1.034 M Standard hydrochloric acid 1.034 M 標準氫氯酸溶液 |
|---|---|
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0.209 M Standard hydrochloric acid 0.200 M 標準氫氯酸溶液 |
 |
Methyl orange 甲基橙指示劑 |
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Weigh a sample of unknown mixture accurately. 稱量樣本以得出樣本的重量。 |
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Stir the sample with water. 將樣本溶於水中並加以攪拌。 |
 |
Filter the suspension to collect the filtrate. 透過過濾法得到濾液。 |
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Fill the burette with standard hydrochloric acid. Make sure that the burette is rinsed before use. 將標準氫氯酸溶液裝進滴定管。 請確保滴定管在使用前已洗滌完畢。 |
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Use methyl orange as the indicator. 以甲基橙作為指示劑 。 |
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Titrate the filtrate against standard hydrochloric acid. 用標準氫氯酸溶液與濾液進行滴定。 |
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Method
3 - Direct titration
方法三（直接滴定法）
|
|
1.034 M Standard hydrochloric acid 1.034 M 標準氫氯酸溶液 |
|---|---|
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0.209 M Standard hydrochloric acid 0.209 M 標準氫氯酸溶液 |
|
|
Methyl orange 甲基橙指示劑 |
 |
Weigh a sample of unknown mixture accurately. 稱量樣本以得出樣本的重量。 |
 |
Stir the sample with water. 將樣本溶於水中並加以攪拌。 |
 |
Fill the burette with standard hydrochloric acid. Make sure that the burette is rinsed before use. 將標準氫氯酸溶液裝進滴定管。 請確保滴定管在使用前已洗滌完畢。 |
 |
Use methyl orange as the indicator. 以甲基橙作為指示劑。 |
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Titrate the filtrate against standard hydrochloric acid. 用標準氫氯酸溶液與濾液進行滴定。 |
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Method
4
- Back titration
方法四（返滴定法）
|
|
1.034 M Standard hydrochloric acid 1.034 M 標準氫氯酸溶液 |
|---|---|
|
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0.209 M Standard hydrochloric acid 0.209 M 標準氫氯酸溶液 |
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0.200 M Standard sodium hydroxide solution 0.200 M 標準氫氧化鈉溶液 |
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Phenolphthalein 酚酞指示劑 |
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Weigh a sample of unknown mixture accurately. 稱量樣本以得出樣本的重量。 |
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Stir the sample with water. 將樣本溶於水中並加以攪拌。 |
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Fill the burette with standard sodium hydroxide solution. Make sure that the burette is rinsed before use. 將標準氫氧化鈉溶液裝進滴定管。 請確保滴定管在使用前已洗滌完畢。 |
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Add 50 cm3 of standard hydrochloric acid to the mixture. Make sure that the pipette is rinsed before use. 將50 cm3 標準氫氯酸溶液加入混合物。 請確保移液管在使用前已洗滌完畢。 |
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Use phenolphthalein as the indicator. 以酚酞作為指示劑。 |
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Titrate the filtrate against standard sodium hydroxide solution. 用標準氫氧化鈉溶液與濾液進行滴定。 |
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