Methyl orange shows pink colour in acidic medium and yellow colour in basic medium. Because it changes colour at the pH of a mid strength acid, it is usually used in titration for acids. Unlike a universal indicator, methyl orange does not have a full spectrum of colour change, but it has a sharp end point.
Methyl orange shows pink colour in acidic medium and yellow colour in basic medium. Because it changes colour at the pH of a mid strength acid, it is usually used in titration for acids. Unlike a universal indicator, methyl orange does not have a full spectrum of colour change, but it has a sharp end point.
There are two indicators such as phenolphthalein and methyl orange are used in the Na2CO3 and HCl titration. Out of them, phenolphthalein colour change is easy to spot but methyl orange colour change is difficult to judge.
There are two indicators such as phenolphthalein and methyl orange are used in the Na2CO3 and HCl titration. Out of them, phenolphthalein colour change is easy to spot but methyl orange colour change is difficult to judge.
The methyl orange should encompass all of the alkalinity by converting it all to carbonic acid at an end point around pH 4.2.
Phenolphthalein has an end point of around 8.2pH. At this point all the carbonate alkalinity is converted but only about half of the bicarbonate is converted.
The methyl orange should encompass all of the alkalinity by converting it all to carbonic acid at an end point around pH 4.2.
Phenolphthalein has an end point of around 8.2pH. At this point all the carbonate alkalinity is converted but only about half of the bicarbonate is converted.
Look at the answer of Pete Gannett to “Why is Na2CO3 used as a primary standard?”
But soda isn’t overwhelming good. pH titrations can be problematic, because you can use it against srong acids only (or have to fight with “self produced buffer solutions” obscuring the point of equivalence). The soda used must be good cystallized pure dekahydrate, no impurities of monohydrate or water free carbonate disturbing the weight.
Look at the answer of Pete Gannett to “Why is Na2CO3 used as a primary standard?”
But soda isn’t overwhelming good. pH titrations can be problematic, because you can use it against srong acids only (or have to fight with “self produced buffer solutions” obscuring the point of equivalence). The soda used must be good cystallized pure dekahydrate, no impurities of monohydrate or water free carbonate disturbing the weight.
Although Na2CO3 is salt it hydrolyzes to produce strong alkali NaOH.This NaOH gets titrated.
Although Na2CO3 is salt it hydrolyzes to produce strong alkali NaOH.This NaOH gets titrated.
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Methyl orange shows pink colour in acidic medium and yellow colour in basic medium. Because it changes colour at the pH of a mid strength acid, it is usually used in titration for acids. Unlike a universal indicator, methyl orange does not have a full spectrum of colour change, but it has a sharp end point.
Methyl orange shows pink colour in acidic medium and yellow colour in basic medium. Because it changes colour at the pH of a mid strength acid, it is usually used in titration for acids. Unlike a universal indicator, methyl orange does not have a full spectrum of colour change, but it has a sharp end point.
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There are two indicators such as phenolphthalein and methyl orange are used in the Na2CO3 and HCl titration. Out of them, phenolphthalein colour change is easy to spot but methyl orange colour change is difficult to judge.
There are two indicators such as phenolphthalein and methyl orange are used in the Na2CO3 and HCl titration. Out of them, phenolphthalein colour change is easy to spot but methyl orange colour change is difficult to judge.
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Yes…. sodium carbonate is a primary standard substance and you can standardize HCl with it easily.
As mentioned in the literature you can use methyl orange as an indicator although I always preferred bromothymol blue! ;-)
Yes…. sodium carbonate is a primary standard substance and you can standardize HCl with it easily.
As mentioned in the literature you can use methyl orange as an indicator although I always preferred bromothymol blue! ;-)
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The methyl orange should encompass all of the alkalinity by converting it all to carbonic acid at an end point around pH 4.2.
Phenolphthalein has an end point of around 8.2pH. At this point all the carbonate alkalinity is converted but only about half of the bicarbonate is converted.
The methyl orange should encompass all of the alkalinity by converting it all to carbonic acid at an end point around pH 4.2.
Phenolphthalein has an end point of around 8.2pH. At this point all the carbonate alkalinity is converted but only about half of the bicarbonate is converted.
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You need two indicators because the reaction has two end points
Phenolphthalein changes to clear at the first end point. Add some methyl orange to get the second end point.
[math]Na_2CO_3 + HCl = NaHCO_3 + NaCl[/math]
[math]NaHCO_3 + HCl = CO_2 + H_2O + NaCl[/math]
You need two indicators because the reaction has two end points
Phenolphthalein changes to clear at the first end point. Add some methyl orange to get the second end point.
[math]Na_2CO_3 + HCl = NaHCO_3 + NaCl[/math]
[math]NaHCO_3 + HCl = CO_2 + H_2O + NaCl[/math]
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Look at the answer of Pete Gannett to “Why is Na2CO3 used as a primary standard?”
But soda isn’t overwhelming good. pH titrations can be problematic, because you can use it against srong acids only (or have to fight with “self produced buffer solutions” obscuring the point of equivalence). The soda used must be good cystallized pure dekahydrate, no impurities of monohydrate or water free carbonate disturbing the weight.
Look at the answer of Pete Gannett to “Why is Na2CO3 used as a primary standard?”
But soda isn’t overwhelming good. pH titrations can be problematic, because you can use it against srong acids only (or have to fight with “self produced buffer solutions” obscuring the point of equivalence). The soda used must be good cystallized pure dekahydrate, no impurities of monohydrate or water free carbonate disturbing the weight.
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There is no reason to boil the solution after the titration. After the titration, you are done, it doesn't make any sense to boil the solution.
But it does make sense to boil the solution during the titration: Why during titration of HCL and Na2CO3 the solution is boiled just before reaching the second equivalence point?
There is no reason to boil the solution after the titration. After the titration, you are done, it doesn't make any sense to boil the solution.
But it does make sense to boil the solution during the titration: Why during titration of HCL and Na2CO3 the solution is boiled just before reaching the second equivalence point?
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