The water sample does not contain Oh- and HCO3 - ions together gove reason
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Answered by
41
Alkalinity means the find the amount of acid neutralizing in water. Alkalinity is the total of all bases that occupying in the water and basically find in carbonate, bicarbonate and hydroxide. More alkalinity level can make scale formation. Total Alkalinity maximum level is 500 mg/l.
The alkalinity of water is attributed to the presence of the following substances in it
Caustic alkalinity
Sodium or potassium hydroxides (NaOH or KOH)
Sodium or potassium carbonates (Na2C03 or K2CO3)
Sodium or potassium bicarbonates (NaHCO3 or KHCO3)
Temporary Hardness
Calcium bicarbonate [Ca(HCO3)2]
Magnesium bicarbonate [Mg(HCO3)2]
These can be estimated separately by titration against standard acid using phenolphthalein and methyl orange indicators. The determination is based on the following reaction.
(i) [OH–] + [H+] ——-> H2O
(ii) [CO32-] + [H+] —–> [HCO3–]
(iii) [HCO3 –] + [H+] ——> H2O + CO2
The titration of the water sample against a standard acid upto phenolphthalein end-point marks that completion of reactions (i) and (ii) only. This amount of acid used thus corresponds to hydroxide plus one-half of the normal carbonate present. On the other hand, titration of the water sample against a standard acid to methyl orange end•point marks the completion of reactions (i), (ii) and (iii).
Hence. the amount of acid used alter the phenolphthalein end•point corresponds to one-half of normal carbonate plus all the bicarbonates ; while the total amount of acid represents the total alkalinity (due to hydroxide bicarbonate and carbonates).
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The alkalinity of water is attributed to the presence of the following substances in it
Caustic alkalinity
Sodium or potassium hydroxides (NaOH or KOH)
Sodium or potassium carbonates (Na2C03 or K2CO3)
Sodium or potassium bicarbonates (NaHCO3 or KHCO3)
Temporary Hardness
Calcium bicarbonate [Ca(HCO3)2]
Magnesium bicarbonate [Mg(HCO3)2]
These can be estimated separately by titration against standard acid using phenolphthalein and methyl orange indicators. The determination is based on the following reaction.
(i) [OH–] + [H+] ——-> H2O
(ii) [CO32-] + [H+] —–> [HCO3–]
(iii) [HCO3 –] + [H+] ——> H2O + CO2
The titration of the water sample against a standard acid upto phenolphthalein end-point marks that completion of reactions (i) and (ii) only. This amount of acid used thus corresponds to hydroxide plus one-half of the normal carbonate present. On the other hand, titration of the water sample against a standard acid to methyl orange end•point marks the completion of reactions (i), (ii) and (iii).
Hence. the amount of acid used alter the phenolphthalein end•point corresponds to one-half of normal carbonate plus all the bicarbonates ; while the total amount of acid represents the total alkalinity (due to hydroxide bicarbonate and carbonates).
PLEASE MAKE MY ANSWER BRAINLIEST ....
Answered by
20
Hey dear,
● Why the water sample doesn't contain OH- and HCO3- ions together ?
- OH- ions as well as HCO3- ions have same negative charge.
- Two negative ions can't be found together.
OH- + HCO3- ---> NO REACTION
- Therefore, OH- and HCO3- ions can't be observed in a single water sample.
Hope this helps you .
Keep asking..
● Why the water sample doesn't contain OH- and HCO3- ions together ?
- OH- ions as well as HCO3- ions have same negative charge.
- Two negative ions can't be found together.
OH- + HCO3- ---> NO REACTION
- Therefore, OH- and HCO3- ions can't be observed in a single water sample.
Hope this helps you .
Keep asking..
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